Updating all of the new ones that are done.
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# Beer Song
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Write a program which produces the lyrics to that beloved classic, that field-trip favorite: 99 Bottles of Beer on the Wall.
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Note that not all verses are identical.
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```plain
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99 bottles of beer on the wall, 99 bottles of beer.
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Take one down and pass it around, 98 bottles of beer on the wall.
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98 bottles of beer on the wall, 98 bottles of beer.
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Take one down and pass it around, 97 bottles of beer on the wall.
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97 bottles of beer on the wall, 97 bottles of beer.
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Take one down and pass it around, 96 bottles of beer on the wall.
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96 bottles of beer on the wall, 96 bottles of beer.
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Take one down and pass it around, 95 bottles of beer on the wall.
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95 bottles of beer on the wall, 95 bottles of beer.
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Take one down and pass it around, 94 bottles of beer on the wall.
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94 bottles of beer on the wall, 94 bottles of beer.
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Take one down and pass it around, 93 bottles of beer on the wall.
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93 bottles of beer on the wall, 93 bottles of beer.
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Take one down and pass it around, 92 bottles of beer on the wall.
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92 bottles of beer on the wall, 92 bottles of beer.
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Take one down and pass it around, 91 bottles of beer on the wall.
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91 bottles of beer on the wall, 91 bottles of beer.
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Take one down and pass it around, 90 bottles of beer on the wall.
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90 bottles of beer on the wall, 90 bottles of beer.
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Take one down and pass it around, 89 bottles of beer on the wall.
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89 bottles of beer on the wall, 89 bottles of beer.
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Take one down and pass it around, 88 bottles of beer on the wall.
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88 bottles of beer on the wall, 88 bottles of beer.
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Take one down and pass it around, 87 bottles of beer on the wall.
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87 bottles of beer on the wall, 87 bottles of beer.
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Take one down and pass it around, 86 bottles of beer on the wall.
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86 bottles of beer on the wall, 86 bottles of beer.
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Take one down and pass it around, 85 bottles of beer on the wall.
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85 bottles of beer on the wall, 85 bottles of beer.
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Take one down and pass it around, 84 bottles of beer on the wall.
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84 bottles of beer on the wall, 84 bottles of beer.
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Take one down and pass it around, 83 bottles of beer on the wall.
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83 bottles of beer on the wall, 83 bottles of beer.
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Take one down and pass it around, 82 bottles of beer on the wall.
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82 bottles of beer on the wall, 82 bottles of beer.
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Take one down and pass it around, 81 bottles of beer on the wall.
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81 bottles of beer on the wall, 81 bottles of beer.
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Take one down and pass it around, 80 bottles of beer on the wall.
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80 bottles of beer on the wall, 80 bottles of beer.
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Take one down and pass it around, 79 bottles of beer on the wall.
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79 bottles of beer on the wall, 79 bottles of beer.
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Take one down and pass it around, 78 bottles of beer on the wall.
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78 bottles of beer on the wall, 78 bottles of beer.
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Take one down and pass it around, 77 bottles of beer on the wall.
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77 bottles of beer on the wall, 77 bottles of beer.
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Take one down and pass it around, 76 bottles of beer on the wall.
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76 bottles of beer on the wall, 76 bottles of beer.
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Take one down and pass it around, 75 bottles of beer on the wall.
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75 bottles of beer on the wall, 75 bottles of beer.
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Take one down and pass it around, 74 bottles of beer on the wall.
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74 bottles of beer on the wall, 74 bottles of beer.
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Take one down and pass it around, 73 bottles of beer on the wall.
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73 bottles of beer on the wall, 73 bottles of beer.
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Take one down and pass it around, 72 bottles of beer on the wall.
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72 bottles of beer on the wall, 72 bottles of beer.
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Take one down and pass it around, 71 bottles of beer on the wall.
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71 bottles of beer on the wall, 71 bottles of beer.
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Take one down and pass it around, 70 bottles of beer on the wall.
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70 bottles of beer on the wall, 70 bottles of beer.
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Take one down and pass it around, 69 bottles of beer on the wall.
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69 bottles of beer on the wall, 69 bottles of beer.
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Take one down and pass it around, 68 bottles of beer on the wall.
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68 bottles of beer on the wall, 68 bottles of beer.
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Take one down and pass it around, 67 bottles of beer on the wall.
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67 bottles of beer on the wall, 67 bottles of beer.
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Take one down and pass it around, 66 bottles of beer on the wall.
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66 bottles of beer on the wall, 66 bottles of beer.
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Take one down and pass it around, 65 bottles of beer on the wall.
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65 bottles of beer on the wall, 65 bottles of beer.
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Take one down and pass it around, 64 bottles of beer on the wall.
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64 bottles of beer on the wall, 64 bottles of beer.
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Take one down and pass it around, 63 bottles of beer on the wall.
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63 bottles of beer on the wall, 63 bottles of beer.
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Take one down and pass it around, 62 bottles of beer on the wall.
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62 bottles of beer on the wall, 62 bottles of beer.
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Take one down and pass it around, 61 bottles of beer on the wall.
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61 bottles of beer on the wall, 61 bottles of beer.
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Take one down and pass it around, 60 bottles of beer on the wall.
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60 bottles of beer on the wall, 60 bottles of beer.
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Take one down and pass it around, 59 bottles of beer on the wall.
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59 bottles of beer on the wall, 59 bottles of beer.
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Take one down and pass it around, 58 bottles of beer on the wall.
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58 bottles of beer on the wall, 58 bottles of beer.
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Take one down and pass it around, 57 bottles of beer on the wall.
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57 bottles of beer on the wall, 57 bottles of beer.
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Take one down and pass it around, 56 bottles of beer on the wall.
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56 bottles of beer on the wall, 56 bottles of beer.
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Take one down and pass it around, 55 bottles of beer on the wall.
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55 bottles of beer on the wall, 55 bottles of beer.
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Take one down and pass it around, 54 bottles of beer on the wall.
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54 bottles of beer on the wall, 54 bottles of beer.
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Take one down and pass it around, 53 bottles of beer on the wall.
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53 bottles of beer on the wall, 53 bottles of beer.
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Take one down and pass it around, 52 bottles of beer on the wall.
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52 bottles of beer on the wall, 52 bottles of beer.
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Take one down and pass it around, 51 bottles of beer on the wall.
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51 bottles of beer on the wall, 51 bottles of beer.
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Take one down and pass it around, 50 bottles of beer on the wall.
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50 bottles of beer on the wall, 50 bottles of beer.
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Take one down and pass it around, 49 bottles of beer on the wall.
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49 bottles of beer on the wall, 49 bottles of beer.
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Take one down and pass it around, 48 bottles of beer on the wall.
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48 bottles of beer on the wall, 48 bottles of beer.
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Take one down and pass it around, 47 bottles of beer on the wall.
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47 bottles of beer on the wall, 47 bottles of beer.
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Take one down and pass it around, 46 bottles of beer on the wall.
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46 bottles of beer on the wall, 46 bottles of beer.
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Take one down and pass it around, 45 bottles of beer on the wall.
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45 bottles of beer on the wall, 45 bottles of beer.
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Take one down and pass it around, 44 bottles of beer on the wall.
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44 bottles of beer on the wall, 44 bottles of beer.
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Take one down and pass it around, 43 bottles of beer on the wall.
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43 bottles of beer on the wall, 43 bottles of beer.
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Take one down and pass it around, 42 bottles of beer on the wall.
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42 bottles of beer on the wall, 42 bottles of beer.
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Take one down and pass it around, 41 bottles of beer on the wall.
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41 bottles of beer on the wall, 41 bottles of beer.
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Take one down and pass it around, 40 bottles of beer on the wall.
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40 bottles of beer on the wall, 40 bottles of beer.
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Take one down and pass it around, 39 bottles of beer on the wall.
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39 bottles of beer on the wall, 39 bottles of beer.
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Take one down and pass it around, 38 bottles of beer on the wall.
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38 bottles of beer on the wall, 38 bottles of beer.
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Take one down and pass it around, 37 bottles of beer on the wall.
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37 bottles of beer on the wall, 37 bottles of beer.
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Take one down and pass it around, 36 bottles of beer on the wall.
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36 bottles of beer on the wall, 36 bottles of beer.
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Take one down and pass it around, 35 bottles of beer on the wall.
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35 bottles of beer on the wall, 35 bottles of beer.
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Take one down and pass it around, 34 bottles of beer on the wall.
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34 bottles of beer on the wall, 34 bottles of beer.
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Take one down and pass it around, 33 bottles of beer on the wall.
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33 bottles of beer on the wall, 33 bottles of beer.
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Take one down and pass it around, 32 bottles of beer on the wall.
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32 bottles of beer on the wall, 32 bottles of beer.
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Take one down and pass it around, 31 bottles of beer on the wall.
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31 bottles of beer on the wall, 31 bottles of beer.
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Take one down and pass it around, 30 bottles of beer on the wall.
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30 bottles of beer on the wall, 30 bottles of beer.
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Take one down and pass it around, 29 bottles of beer on the wall.
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29 bottles of beer on the wall, 29 bottles of beer.
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Take one down and pass it around, 28 bottles of beer on the wall.
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28 bottles of beer on the wall, 28 bottles of beer.
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Take one down and pass it around, 27 bottles of beer on the wall.
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27 bottles of beer on the wall, 27 bottles of beer.
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Take one down and pass it around, 26 bottles of beer on the wall.
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26 bottles of beer on the wall, 26 bottles of beer.
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Take one down and pass it around, 25 bottles of beer on the wall.
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25 bottles of beer on the wall, 25 bottles of beer.
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Take one down and pass it around, 24 bottles of beer on the wall.
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24 bottles of beer on the wall, 24 bottles of beer.
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Take one down and pass it around, 23 bottles of beer on the wall.
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23 bottles of beer on the wall, 23 bottles of beer.
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Take one down and pass it around, 22 bottles of beer on the wall.
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22 bottles of beer on the wall, 22 bottles of beer.
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Take one down and pass it around, 21 bottles of beer on the wall.
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21 bottles of beer on the wall, 21 bottles of beer.
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Take one down and pass it around, 20 bottles of beer on the wall.
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20 bottles of beer on the wall, 20 bottles of beer.
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Take one down and pass it around, 19 bottles of beer on the wall.
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19 bottles of beer on the wall, 19 bottles of beer.
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Take one down and pass it around, 18 bottles of beer on the wall.
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18 bottles of beer on the wall, 18 bottles of beer.
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Take one down and pass it around, 17 bottles of beer on the wall.
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17 bottles of beer on the wall, 17 bottles of beer.
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Take one down and pass it around, 16 bottles of beer on the wall.
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16 bottles of beer on the wall, 16 bottles of beer.
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Take one down and pass it around, 15 bottles of beer on the wall.
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15 bottles of beer on the wall, 15 bottles of beer.
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Take one down and pass it around, 14 bottles of beer on the wall.
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14 bottles of beer on the wall, 14 bottles of beer.
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Take one down and pass it around, 13 bottles of beer on the wall.
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13 bottles of beer on the wall, 13 bottles of beer.
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Take one down and pass it around, 12 bottles of beer on the wall.
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12 bottles of beer on the wall, 12 bottles of beer.
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Take one down and pass it around, 11 bottles of beer on the wall.
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11 bottles of beer on the wall, 11 bottles of beer.
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Take one down and pass it around, 10 bottles of beer on the wall.
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10 bottles of beer on the wall, 10 bottles of beer.
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Take one down and pass it around, 9 bottles of beer on the wall.
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9 bottles of beer on the wall, 9 bottles of beer.
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Take one down and pass it around, 8 bottles of beer on the wall.
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8 bottles of beer on the wall, 8 bottles of beer.
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Take one down and pass it around, 7 bottles of beer on the wall.
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7 bottles of beer on the wall, 7 bottles of beer.
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Take one down and pass it around, 6 bottles of beer on the wall.
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6 bottles of beer on the wall, 6 bottles of beer.
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Take one down and pass it around, 5 bottles of beer on the wall.
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5 bottles of beer on the wall, 5 bottles of beer.
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Take one down and pass it around, 4 bottles of beer on the wall.
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4 bottles of beer on the wall, 4 bottles of beer.
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Take one down and pass it around, 3 bottles of beer on the wall.
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3 bottles of beer on the wall, 3 bottles of beer.
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Take one down and pass it around, 2 bottles of beer on the wall.
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2 bottles of beer on the wall, 2 bottles of beer.
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Take one down and pass it around, 1 bottle of beer on the wall.
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1 bottle of beer on the wall, 1 bottle of beer.
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Take it down and pass it around, no more bottles of beer on the wall.
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No more bottles of beer on the wall, no more bottles of beer.
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Go to the store and buy some more, 99 bottles of beer on the wall.
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```
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## For bonus points
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Did you get the tests passing and the code clean? If you want to, these
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are some additional things you could try:
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* Remove as much duplication as you possibly can.
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* Optimize for readability, even if it means introducing duplication.
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* If you've removed all the duplication, do you have a lot of
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conditionals? Try replacing the conditionals with polymorphism, if it
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applies in this language. How readable is it?
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Then please share your thoughts in a comment on the submission. Did this
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experiment make the code better? Worse? Did you learn anything from it?
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To run the tests simply run the command `go test` in the exercise directory.
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If the test suite contains benchmarks, you can run these with the `-bench`
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flag:
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go test -bench .
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For more detailed info about the Go track see the [help
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page](http://exercism.io/languages/go).
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## Source
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Learn to Program by Chris Pine [http://pine.fm/LearnToProgram/?Chapter=06](http://pine.fm/LearnToProgram/?Chapter=06)
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## Submitting Incomplete Problems
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It's possible to submit an incomplete solution so you can see how others have completed the exercise.
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@ -0,0 +1,66 @@
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package beer
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import (
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"errors"
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"strconv"
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"strings"
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)
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// buildBase builds the basic "x bottle(s) of beer"
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func buildBase(num int) string {
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var ret string
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if num == 0 {
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ret = "No more"
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} else {
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ret = strconv.Itoa(num)
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}
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ret += " bottle"
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if num != 1 {
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ret += "s"
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}
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ret += " of beer"
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return ret
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}
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// Verse generates a single verse
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func Verse(num int) (string, error) {
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var ret string
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if num > 99 || num < 0 {
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return "", errors.New("Invalid verse requested")
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}
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ret += buildBase(num) + " on the wall, " + strings.ToLower(buildBase(num)) + ".\n"
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if num == 0 {
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ret += "Go to the store and buy some more, " + buildBase(99) + " on the wall.\n"
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} else {
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ret += "Take "
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if num == 1 {
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ret += "it "
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} else {
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ret += "one "
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}
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ret += "down and pass it around, " + strings.ToLower(buildBase(num-1)) + " on the wall.\n"
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}
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return ret, nil
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}
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// Verses generates all verses starting at 'st' and going to 'end'
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func Verses(st, end int) (string, error) {
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if st < end {
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return "", errors.New("Start less than stop")
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}
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var r, ret string
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var err error
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for i := st; i >= end; i-- {
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if r, err = Verse(i); err != nil {
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return "", err
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}
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ret += r + "\n"
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}
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return ret, nil
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}
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// Song generates the entire song (all 100 verses)
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func Song() string {
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r, _ := Verses(99, 0)
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return r
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}
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@ -0,0 +1,139 @@
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package beer
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import (
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"testing"
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)
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const verse8 = "8 bottles of beer on the wall, 8 bottles of beer.\nTake one down and pass it around, 7 bottles of beer on the wall.\n"
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const verse3 = "3 bottles of beer on the wall, 3 bottles of beer.\nTake one down and pass it around, 2 bottles of beer on the wall.\n"
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const verse2 = "2 bottles of beer on the wall, 2 bottles of beer.\nTake one down and pass it around, 1 bottle of beer on the wall.\n"
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const verse1 = "1 bottle of beer on the wall, 1 bottle of beer.\nTake it down and pass it around, no more bottles of beer on the wall.\n"
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const verse0 = "No more bottles of beer on the wall, no more bottles of beer.\nGo to the store and buy some more, 99 bottles of beer on the wall.\n"
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const verses86 = `8 bottles of beer on the wall, 8 bottles of beer.
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Take one down and pass it around, 7 bottles of beer on the wall.
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7 bottles of beer on the wall, 7 bottles of beer.
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Take one down and pass it around, 6 bottles of beer on the wall.
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6 bottles of beer on the wall, 6 bottles of beer.
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Take one down and pass it around, 5 bottles of beer on the wall.
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`
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const verses75 = `7 bottles of beer on the wall, 7 bottles of beer.
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Take one down and pass it around, 6 bottles of beer on the wall.
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6 bottles of beer on the wall, 6 bottles of beer.
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Take one down and pass it around, 5 bottles of beer on the wall.
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5 bottles of beer on the wall, 5 bottles of beer.
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Take one down and pass it around, 4 bottles of beer on the wall.
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`
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var verseTestCases = []struct {
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description string
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verse int
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expectedVerse string
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expectErr bool
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}{
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{"a typical verse", 8, verse8, false},
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{"another typical verse", 3, verse3, false},
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{"verse 2", 2, verse2, false},
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{"verse 1", 1, verse1, false},
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{"verse 0", 0, verse0, false},
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{"invalid verse", 104, "", true},
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}
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func TestBottlesVerse(t *testing.T) {
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for _, tt := range verseTestCases {
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actualVerse, err := Verse(tt.verse)
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if actualVerse != tt.expectedVerse {
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t.Fatalf("Verse(%d):\nexpected\n%s\nactual\n%s", tt.verse, tt.expectedVerse, actualVerse)
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}
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// if we expect an error and there isn't one
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if tt.expectErr && err == nil {
|
||||
t.Errorf("Verse(%d): expected an error, but error is nil", tt.verse)
|
||||
}
|
||||
// if we don't expect an error and there is one
|
||||
if !tt.expectErr && err != nil {
|
||||
t.Errorf("Verse(%d): expected no error, but error is: %s", tt.verse, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
var versesTestCases = []struct {
|
||||
description string
|
||||
upperBound int
|
||||
lowerBound int
|
||||
expectedVerse string
|
||||
expectErr bool
|
||||
}{
|
||||
{"multiple verses", 8, 6, verses86, false},
|
||||
{"a different set of verses", 7, 5, verses75, false},
|
||||
{"invalid start", 109, 5, "", true},
|
||||
{"invalid stop", 99, -20, "", true},
|
||||
{"start less than stop", 8, 14, "", true},
|
||||
}
|
||||
|
||||
func TestSeveralVerses(t *testing.T) {
|
||||
|
||||
for _, tt := range versesTestCases {
|
||||
actualVerse, err := Verses(tt.upperBound, tt.lowerBound)
|
||||
if actualVerse != tt.expectedVerse {
|
||||
t.Fatalf("Verses(%d, %d):\nexpected\n%s\nactual\n%s", tt.upperBound, tt.lowerBound, tt.expectedVerse, actualVerse)
|
||||
}
|
||||
// if we expect an error and there isn't one
|
||||
if tt.expectErr && err == nil {
|
||||
t.Errorf("Verses(%d, %d): expected an error, but error is nil", tt.upperBound, tt.lowerBound)
|
||||
}
|
||||
// if we don't expect an error and there is one
|
||||
if !tt.expectErr && err != nil {
|
||||
t.Errorf("Verses(%d, %d): expected no error, but error is: %s", tt.upperBound, tt.lowerBound, err)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkSeveralVerses(b *testing.B) {
|
||||
b.StopTimer()
|
||||
for _, tt := range versesTestCases {
|
||||
b.StartTimer()
|
||||
|
||||
for i := 0; i < b.N; i++ {
|
||||
Verses(tt.upperBound, tt.lowerBound)
|
||||
}
|
||||
|
||||
b.StopTimer()
|
||||
}
|
||||
}
|
||||
|
||||
func TestEntireSong(t *testing.T) {
|
||||
expected, err := Verses(99, 0)
|
||||
if err != nil {
|
||||
t.Fatalf("unexpected error calling Verses(99,0)")
|
||||
}
|
||||
actual := Song()
|
||||
|
||||
if expected != actual {
|
||||
msg := `
|
||||
Did not sing the whole song correctly.
|
||||
|
||||
Expected:
|
||||
|
||||
%v
|
||||
|
||||
Actual:
|
||||
|
||||
%v
|
||||
`
|
||||
t.Fatalf(msg, expected, actual)
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkEntireSong(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
Song()
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,56 @@
|
|||
# Diffie Hellman
|
||||
|
||||
Diffie-Hellman key exchange.
|
||||
|
||||
Alice and Bob use Diffie-Hellman key exchange to share secrets. They
|
||||
start with prime numbers, pick private keys, generate and share public
|
||||
keys, and then generate a shared secret key.
|
||||
|
||||
## Step 0
|
||||
|
||||
The test program supplies prime numbers p and g.
|
||||
|
||||
## Step 1
|
||||
|
||||
Alice picks a private key, a, greater than 1 and less than p. Bob does
|
||||
the same to pick a private key b.
|
||||
|
||||
## Step 2
|
||||
|
||||
Alice calculates a public key A.
|
||||
|
||||
A = g**a mod p
|
||||
|
||||
Using the same p and g, Bob similarly calculates a public key B from his
|
||||
private key b.
|
||||
|
||||
## Step 3
|
||||
|
||||
Alice and Bob exchange public keys. Alice calculates secret key s.
|
||||
|
||||
s = B**a mod p
|
||||
|
||||
Bob calculates
|
||||
|
||||
s = A**b mod p
|
||||
|
||||
The calculations produce the same result! Alice and Bob now share
|
||||
secret s.
|
||||
|
||||
To run the tests simply run the command `go test` in the exercise directory.
|
||||
|
||||
If the test suite contains benchmarks, you can run these with the `-bench`
|
||||
flag:
|
||||
|
||||
go test -bench .
|
||||
|
||||
For more detailed info about the Go track see the [help
|
||||
page](http://exercism.io/languages/go).
|
||||
|
||||
## Source
|
||||
|
||||
Wikipedia, 1024 bit key from www.cryptopp.com/wiki. [http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange](http://en.wikipedia.org/wiki/Diffie%E2%80%93Hellman_key_exchange)
|
||||
|
||||
## Submitting Incomplete Problems
|
||||
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|
||||
|
||||
|
|
@ -0,0 +1,183 @@
|
|||
// Diffie-Hellman-Merkle key exchange
|
||||
//
|
||||
// Step 1: PrivateKey(p *big.Int) *big.Int
|
||||
// Step 2: PublicKey(private, p *big.Int, g int64) *big.Int
|
||||
// Step 2.1: NewPair(p *big.Int, g int64) (private, public *big.Int)
|
||||
// Step 3: SecretKey(private1, public2, p *big.Int) *big.Int
|
||||
//
|
||||
// Private keys should be generated randomly.
|
||||
|
||||
package diffiehellman
|
||||
|
||||
import (
|
||||
"math/big"
|
||||
"testing"
|
||||
)
|
||||
|
||||
type testCase struct {
|
||||
g int64 // prime, generator
|
||||
p *big.Int // prime, modulus
|
||||
a, b *big.Int // private keys
|
||||
A, B *big.Int // public keys
|
||||
s *big.Int // secret key
|
||||
}
|
||||
|
||||
// WP example
|
||||
var smallTest = testCase{
|
||||
5,
|
||||
big.NewInt(23),
|
||||
big.NewInt(6), big.NewInt(15),
|
||||
big.NewInt(8), big.NewInt(19),
|
||||
big.NewInt(2),
|
||||
}
|
||||
|
||||
// 1024 bit example modulus from cryptopp.com wiki, random private keys
|
||||
var biggerTest = testCase{
|
||||
2,
|
||||
mph("ab359aa76a6773ed7a93b214db0c25d0160817b8a893c001c761e198a3694509" +
|
||||
"ebe87a5313e0349d95083e5412c9fc815bfd61f95ddece43376550fdc624e92f" +
|
||||
"f38a415783b97261204e05d65731bba1ccff0e84c8cd2097b75feca1029261ae" +
|
||||
"19a389a2e15d2939314b184aef707b82eb94412065181d23e04bf065f4ac413f"),
|
||||
|
||||
mph("2f6afe91cb53ecfa463d45cd800c948f7cb83bb9ddc62a07b5b3fd302d0cdf52" +
|
||||
"18ae53ad015a632d137001a3b34239d54715606a292b6cf895b09d7dcf1bdf7a"),
|
||||
|
||||
mph("3651007bfa8a8b1cbaed2ae9326327599249c3bb6e9d8744b7407f3d4732cb8a" +
|
||||
"0708d95c382747bad640d444f135e7e599618d11b15b9ef32e7ac7194e547f4b"),
|
||||
|
||||
mph("57d5489e3858cbd8fae75120907d1521f8e935cce2206d285b11762847e2a4c4" +
|
||||
"a341a4eea18bdd8b40036c8d0004ffc323d5ae19da55176b08ff6f2d0ac97c65" +
|
||||
"357c1f16756a6901ff926c8544c8af0a90ed2705966851f79a115cb77aac66be" +
|
||||
"ceff569aadd7f02859539c28d55c08c62a03e45613bc52d205ace0704ea7c610"),
|
||||
|
||||
mph("6b189a36db5ca3ff83b66fb2c226078294c323f4c7cef35c506c237b0db7906d" +
|
||||
"64cceb05af15a3603a30fd49834d3a6971d917f520d9a577c159d3b7d2bd8813" +
|
||||
"5d19db47a9618340e4a51ec8845dbf5d50a4c6f14d6161def1eeaacecee8018f" +
|
||||
"8816113a294959399989b759f4618e35dbffc570ab2a5a74ac59fccef35f684c"),
|
||||
|
||||
mph("64f74babc466f8e56d9b77ce2cc65d65fe1603b931c018b98a2a615d66172590" +
|
||||
"803a94ac230db02de4b8ae567497c1844a6f7bd5bed69b95d3137acc1a6462d5" +
|
||||
"aeba5b2b83a0e6b8ed4c072e5135a57c87b654ebe04cf128bbff49ee06df33b7" +
|
||||
"8615e0067fdc9df22f7673b1e0501fb57598c7bff9ff173ddff47270fbd6f98f"),
|
||||
}
|
||||
|
||||
// must parse hex, short name contrived just to make test data line up with
|
||||
// tab width 4.
|
||||
func mph(h string) *big.Int {
|
||||
p, ok := new(big.Int).SetString(h, 16)
|
||||
if !ok {
|
||||
panic("invalid hex: " + h)
|
||||
}
|
||||
return p
|
||||
}
|
||||
|
||||
var tests = []testCase{
|
||||
smallTest,
|
||||
biggerTest,
|
||||
}
|
||||
|
||||
var _one = big.NewInt(1)
|
||||
|
||||
// test that PrivateKey returns numbers in range, returns different numbers.
|
||||
func TestPrivateKey(t *testing.T) {
|
||||
priv := func(p *big.Int) *big.Int {
|
||||
a := PrivateKey(p)
|
||||
if a.Cmp(_one) <= 0 || a.Cmp(p) >= 0 {
|
||||
t.Fatalf("PrivateKey(%d) = %d, out of range (1, %d)", p, a, p)
|
||||
}
|
||||
return a
|
||||
}
|
||||
ms := map[string]bool{}
|
||||
mb := map[string]bool{}
|
||||
for i := 0; i < 100; i++ {
|
||||
ms[priv(smallTest.p).String()] = true
|
||||
mb[priv(biggerTest.p).String()] = true
|
||||
}
|
||||
if len(ms) == 1 {
|
||||
t.Fatalf("For prime %d same key generated every time. "+
|
||||
"Want random keys.", smallTest.p)
|
||||
}
|
||||
if len(mb) < 100 {
|
||||
t.Fatal("For prime %d duplicate keys generated. "+
|
||||
"Want unique keys.", biggerTest.p)
|
||||
}
|
||||
}
|
||||
|
||||
// test that PublicKey returns known results.
|
||||
func TestPublicKey(t *testing.T) {
|
||||
tp := func(a, A, p *big.Int, g int64) {
|
||||
if k := PublicKey(a, p, g); k.Cmp(A) != 0 {
|
||||
t.Fatalf("PublicKey(%x,\n%x,\n%d)\n= %x,\nwant %x.",
|
||||
a, p, g, k, A)
|
||||
}
|
||||
}
|
||||
for _, test := range tests {
|
||||
tp(test.a, test.A, test.p, test.g)
|
||||
tp(test.b, test.B, test.p, test.g)
|
||||
}
|
||||
}
|
||||
|
||||
// test that SecretKey returns known results.
|
||||
func TestSecretKeys(t *testing.T) {
|
||||
tp := func(a, B, p, s *big.Int) {
|
||||
if k := SecretKey(a, B, p); k.Cmp(s) != 0 {
|
||||
t.Fatalf("SecretKey(%x,\n%x,\n%x)\n= %x,\nwant %x.",
|
||||
a, B, p, k, s)
|
||||
}
|
||||
}
|
||||
for _, test := range tests {
|
||||
tp(test.a, test.B, test.p, test.s)
|
||||
tp(test.b, test.A, test.p, test.s)
|
||||
}
|
||||
}
|
||||
|
||||
// test that NewPair produces working keys
|
||||
func TestNewPair(t *testing.T) {
|
||||
p, g := biggerTest.p, biggerTest.g
|
||||
test := func(a, A *big.Int) {
|
||||
if a.Cmp(_one) <= 0 || a.Cmp(p) >= 0 {
|
||||
t.Fatalf("NewPair(%d, %d) private key = %d, out of range (1, %d)",
|
||||
p, g, a, p)
|
||||
}
|
||||
if A.Cmp(_one) <= 0 || A.Cmp(p) >= 0 {
|
||||
t.Fatalf("NewPair(%d, %d) public key = %d, out of range (1, %d)",
|
||||
p, g, A, p)
|
||||
}
|
||||
}
|
||||
a, A := NewPair(p, g)
|
||||
test(a, A)
|
||||
for i := 0; i < 20; i++ {
|
||||
b, B := NewPair(p, g)
|
||||
test(b, B)
|
||||
sa := SecretKey(a, B, p)
|
||||
sb := SecretKey(b, A, p)
|
||||
if sa.Cmp(sb) != 0 {
|
||||
t.Fatalf("NewPair() produced non-working keys.")
|
||||
}
|
||||
a, A = b, B
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkPrivateKey(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
PrivateKey(biggerTest.p)
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkPublicKey(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
PublicKey(biggerTest.a, biggerTest.p, biggerTest.g)
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkNewPair(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
NewPair(biggerTest.p, biggerTest.g)
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkSecretKey(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
SecretKey(biggerTest.a, biggerTest.B, biggerTest.p)
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,34 @@
|
|||
package diffiehellman
|
||||
|
||||
import (
|
||||
"math/big"
|
||||
"math/rand"
|
||||
"time"
|
||||
)
|
||||
|
||||
// Random number generator
|
||||
var rnd = rand.New(rand.NewSource(time.Now().UnixNano()))
|
||||
|
||||
// PrivateKey generates a number greater than 1 and less than p
|
||||
func PrivateKey(p *big.Int) *big.Int {
|
||||
ret := &big.Int{}
|
||||
return ret.Add(big.NewInt(2), ret.Rand(rnd, ret.Sub(p, big.NewInt(2))))
|
||||
}
|
||||
|
||||
// PublicKey generates the public key for private key p
|
||||
func PublicKey(pKey, p *big.Int, g int64) *big.Int {
|
||||
ret := big.NewInt(g)
|
||||
return ret.Exp(ret, pKey, p)
|
||||
}
|
||||
|
||||
// NewPair generates a public/private key pair from given primes p & g
|
||||
func NewPair(p *big.Int, g int64) (*big.Int, *big.Int) {
|
||||
priv := PrivateKey(p)
|
||||
return priv, PublicKey(priv, p, g)
|
||||
}
|
||||
|
||||
// SecretKey returns a secret key given private & public keys and the prime p
|
||||
func SecretKey(priv, pub, p *big.Int) *big.Int {
|
||||
ret := &big.Int{}
|
||||
return ret.Exp(pub, priv, p)
|
||||
}
|
||||
|
|
@ -2,21 +2,21 @@ package prime
|
|||
|
||||
var sieve []int
|
||||
|
||||
// Nth finds the nth prime and 'true' if the 0th prime wasn't requested
|
||||
func Nth(n int) (int, bool) {
|
||||
if len(sieve) == 0 {
|
||||
sieve = append(sieve, 0)
|
||||
sieve = append(sieve, 2)
|
||||
}
|
||||
if n == 0 {
|
||||
return 0, false
|
||||
}
|
||||
|
||||
for i := sieve[len(sieve)-1]; n <= len(sieve); i++ {
|
||||
// Check if i is a prime
|
||||
if len(sieve) == 0 {
|
||||
// Let's just do some initialization
|
||||
sieve = append(sieve, 0)
|
||||
sieve = append(sieve, 2)
|
||||
}
|
||||
sieveLen := len(sieve)
|
||||
for i := sieve[len(sieve)-1]; sieveLen <= n; i++ {
|
||||
isPrime := true
|
||||
for j := 1; j < len(sieve); j++ {
|
||||
for j := 1; j < sieveLen; j++ {
|
||||
if i%sieve[j] == 0 {
|
||||
// Not a prime
|
||||
isPrime = false
|
||||
break
|
||||
}
|
||||
|
|
@ -24,9 +24,7 @@ func Nth(n int) (int, bool) {
|
|||
if isPrime {
|
||||
// Found a new prime
|
||||
sieve = append(sieve, i)
|
||||
if len(sieve) >= n {
|
||||
break
|
||||
}
|
||||
sieveLen = len(sieve)
|
||||
}
|
||||
}
|
||||
return sieve[n], true
|
||||
|
|
|
|||
|
|
@ -0,0 +1,96 @@
|
|||
# Ocr Numbers
|
||||
|
||||
Write a program that, given a 3 x 4 grid of pipes, underscores, and spaces, can determine which number is represented, or whether it is garbled.
|
||||
|
||||
# Step One
|
||||
|
||||
To begin with, convert a simple binary font to a string containing 0 or 1.
|
||||
|
||||
The binary font uses pipes and underscores, four rows high and three columns wide.
|
||||
|
||||
```
|
||||
_ #
|
||||
| | # zero.
|
||||
|_| #
|
||||
# the fourth row is always blank
|
||||
```
|
||||
|
||||
Is converted to "0"
|
||||
|
||||
```
|
||||
#
|
||||
| # one.
|
||||
| #
|
||||
# (blank fourth row)
|
||||
```
|
||||
|
||||
Is converted to "1"
|
||||
|
||||
If the input is the correct size, but not recognizable, your program should return '?'
|
||||
|
||||
If the input is the incorrect size, your program should return an error.
|
||||
|
||||
# Step Two
|
||||
|
||||
Update your program to recognize multi-character binary strings, replacing garbled numbers with ?
|
||||
|
||||
# Step Three
|
||||
|
||||
Update your program to recognize all numbers 0 through 9, both individually and as part of a larger string.
|
||||
|
||||
```
|
||||
_
|
||||
_|
|
||||
|_
|
||||
|
||||
```
|
||||
|
||||
Is converted to "2"
|
||||
|
||||
```
|
||||
_ _ _ _ _ _ _ _ #
|
||||
| _| _||_||_ |_ ||_||_|| | # decimal numbers.
|
||||
||_ _| | _||_| ||_| _||_| #
|
||||
# fourth line is always blank
|
||||
```
|
||||
|
||||
Is converted to "1234567890"
|
||||
|
||||
# Step Four
|
||||
|
||||
Update your program to handle multiple numbers, one per line. When converting several lines, join the lines with commas.
|
||||
|
||||
```
|
||||
_ _
|
||||
| _| _|
|
||||
||_ _|
|
||||
|
||||
_ _
|
||||
|_||_ |_
|
||||
| _||_|
|
||||
|
||||
_ _ _
|
||||
||_||_|
|
||||
||_| _|
|
||||
|
||||
```
|
||||
|
||||
Is converted to "123,456,789"
|
||||
|
||||
To run the tests simply run the command `go test` in the exercise directory.
|
||||
|
||||
If the test suite contains benchmarks, you can run these with the `-bench`
|
||||
flag:
|
||||
|
||||
go test -bench .
|
||||
|
||||
For more detailed info about the Go track see the [help
|
||||
page](http://exercism.io/languages/go).
|
||||
|
||||
## Source
|
||||
|
||||
Inspired by the Bank OCR kata [http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR](http://codingdojo.org/cgi-bin/wiki.pl?KataBankOCR)
|
||||
|
||||
## Submitting Incomplete Problems
|
||||
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|
||||
|
||||
|
|
@ -0,0 +1,65 @@
|
|||
package ocr
|
||||
|
||||
import "strings"
|
||||
|
||||
// recognizeDigit takes a 3x4 grid of pipes, underscores, and spaces
|
||||
// and determines the digit represented.
|
||||
func recognizeDigit(in string) string {
|
||||
switch in {
|
||||
case "\n _ \n| |\n|_|\n ":
|
||||
return "0"
|
||||
case "\n \n |\n |\n ":
|
||||
return "1"
|
||||
case "\n _ \n _|\n|_ \n ":
|
||||
return "2"
|
||||
case "\n _ \n _|\n _|\n ":
|
||||
return "3"
|
||||
case "\n \n|_|\n |\n ":
|
||||
return "4"
|
||||
case "\n _ \n|_ \n _|\n ":
|
||||
return "5"
|
||||
case "\n _ \n|_ \n|_|\n ":
|
||||
return "6"
|
||||
case "\n _ \n |\n |\n ":
|
||||
return "7"
|
||||
case "\n _ \n|_|\n|_|\n ":
|
||||
return "8"
|
||||
case "\n _ \n|_|\n _|\n ":
|
||||
return "9"
|
||||
}
|
||||
return "?"
|
||||
}
|
||||
|
||||
// parseChar takes 3 lines and a number and returns
|
||||
// the string value of that character
|
||||
func parseChar(lines []string, num int) string {
|
||||
startIdx := 3 * num
|
||||
lenNeed := startIdx + 3
|
||||
if len(lines[0]) < lenNeed || len(lines[1]) < lenNeed {
|
||||
return ""
|
||||
}
|
||||
char := "\n" + lines[0][(startIdx+0):(startIdx+3)]
|
||||
char += "\n" + lines[1][(startIdx+0):(startIdx+3)]
|
||||
char += "\n" + lines[2][(startIdx+0):(startIdx+3)]
|
||||
char += "\n" + lines[3][(startIdx+0):(startIdx+3)]
|
||||
return recognizeDigit(char)
|
||||
}
|
||||
|
||||
// Recognize takes a string, splits it up by \n and
|
||||
// then sends 4 line chunks and calls parseChar on it
|
||||
func Recognize(in string) []string {
|
||||
var ret []string
|
||||
lines := strings.Split(in, "\n")
|
||||
numRet := len(lines) / 4
|
||||
for i := 0; i < numRet; i++ {
|
||||
var retString string
|
||||
startIdx := (i * 4) + 1
|
||||
procLines := lines[startIdx : startIdx+4]
|
||||
numChars := len(lines[startIdx]) / 3
|
||||
for j := 0; j < numChars; j++ {
|
||||
retString += parseChar(procLines, j)
|
||||
}
|
||||
ret = append(ret, retString)
|
||||
}
|
||||
return ret
|
||||
}
|
||||
|
|
@ -0,0 +1,130 @@
|
|||
// Go requirements:
|
||||
//
|
||||
// Define a function recognizeDigit as README Step 1 except make it recognize
|
||||
// all ten digits 0 to 9. Pick what you like for parameters and return values
|
||||
// but make it useful as a subroutine for README step 2.
|
||||
//
|
||||
// For README Step 2 define,
|
||||
//
|
||||
// func Recognize(string) []string
|
||||
//
|
||||
// and implement it using recognizeDigit.
|
||||
//
|
||||
// Input strings tested here have a \n at the beginning of each line and
|
||||
// no trailing \n on the last line. (This makes for readable raw string
|
||||
// literals.)
|
||||
//
|
||||
// For bonus points, gracefully handle misformatted data. What should you
|
||||
// do with a partial cell? Discard it? Pad with spaces? Report it with a
|
||||
// "?" character? What should you do if the first character is not \n?
|
||||
|
||||
package ocr
|
||||
|
||||
import (
|
||||
"reflect"
|
||||
"testing"
|
||||
)
|
||||
|
||||
var tests = []struct {
|
||||
in string
|
||||
out []string
|
||||
}{
|
||||
{`
|
||||
_
|
||||
| |
|
||||
|_|
|
||||
`, []string{"0"}},
|
||||
{`
|
||||
|
||||
|
|
||||
|
|
||||
`, []string{"1"}},
|
||||
{`
|
||||
_
|
||||
_|
|
||||
|_
|
||||
`, []string{"2"}},
|
||||
{`
|
||||
_
|
||||
_|
|
||||
_|
|
||||
`, []string{"3"}},
|
||||
{`
|
||||
|
||||
|_|
|
||||
|
|
||||
`, []string{"4"}},
|
||||
{`
|
||||
_
|
||||
|_
|
||||
_|
|
||||
`, []string{"5"}},
|
||||
{`
|
||||
_
|
||||
|_
|
||||
|_|
|
||||
`, []string{"6"}},
|
||||
{`
|
||||
_
|
||||
|
|
||||
|
|
||||
`, []string{"7"}},
|
||||
{`
|
||||
_
|
||||
|_|
|
||||
|_|
|
||||
`, []string{"8"}},
|
||||
{`
|
||||
_
|
||||
|_|
|
||||
_|
|
||||
`, []string{"9"}},
|
||||
{`
|
||||
_
|
||||
|| |
|
||||
||_|
|
||||
`, []string{"10"}},
|
||||
{`
|
||||
|
||||
| |
|
||||
| |
|
||||
`, []string{"?"}},
|
||||
{`
|
||||
_ _ _ _
|
||||
| || | || | | || || |
|
||||
| ||_| ||_| | ||_||_|
|
||||
`, []string{"110101100"}},
|
||||
{`
|
||||
_ _ _
|
||||
| || | || | || || |
|
||||
| | _| ||_| | ||_||_|
|
||||
`, []string{"11?10?1?0"}},
|
||||
{`
|
||||
_ _ _ _ _ _ _ _
|
||||
| _| _||_||_ |_ ||_||_|| |
|
||||
||_ _| | _||_| ||_| _||_|
|
||||
`, []string{"1234567890"}},
|
||||
{`
|
||||
_ _
|
||||
| _| _|
|
||||
||_ _|
|
||||
|
||||
_ _
|
||||
|_||_ |_
|
||||
| _||_|
|
||||
|
||||
_ _ _
|
||||
||_||_|
|
||||
||_| _|
|
||||
`, []string{"123", "456", "789"}},
|
||||
}
|
||||
|
||||
var _ = recognizeDigit // step 1.
|
||||
|
||||
func TestRecognize(t *testing.T) {
|
||||
for _, test := range tests {
|
||||
if res := Recognize(test.in); !reflect.DeepEqual(res, test.out) {
|
||||
t.Fatalf("Recognize(`%s`) = %q, want %q.", test.in, res, test.out)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,59 @@
|
|||
# Octal
|
||||
|
||||
Write a program that will convert a octal number, represented as a string (e.g. '1735263'), to its decimal equivalent using first principles (i.e. no, you may not use built-in or external libraries to accomplish the conversion).
|
||||
|
||||
Implement octal to decimal conversion. Given an octal input
|
||||
string, your program should produce a decimal output.
|
||||
|
||||
## Note
|
||||
- Implement the conversion yourself.
|
||||
Do not use something else to perform the conversion for you.
|
||||
- Treat invalid input as octal 0.
|
||||
|
||||
## About Octal (Base-8)
|
||||
Decimal is a base-10 system.
|
||||
|
||||
A number 233 in base 10 notation can be understood
|
||||
as a linear combination of powers of 10:
|
||||
|
||||
- The rightmost digit gets multiplied by 10^0 = 1
|
||||
- The next number gets multiplied by 10^1 = 10
|
||||
- ...
|
||||
- The *n*th number gets multiplied by 10^*(n-1)*.
|
||||
- All these values are summed.
|
||||
|
||||
So:
|
||||
```
|
||||
233 # decimal
|
||||
= 2*10^2 + 3*10^1 + 3*10^0
|
||||
= 2*100 + 3*10 + 3*1
|
||||
```
|
||||
|
||||
Octal is similar, but uses powers of 8 rather than powers of 10.
|
||||
|
||||
So:
|
||||
```
|
||||
233 # octal
|
||||
= 2*8^2 + 3*8^1 + 3*8^0
|
||||
= 2*64 + 3*8 + 3*1
|
||||
= 128 + 24 + 3
|
||||
= 155
|
||||
```
|
||||
|
||||
To run the tests simply run the command `go test` in the exercise directory.
|
||||
|
||||
If the test suite contains benchmarks, you can run these with the `-bench`
|
||||
flag:
|
||||
|
||||
go test -bench .
|
||||
|
||||
For more detailed info about the Go track see the [help
|
||||
page](http://exercism.io/languages/go).
|
||||
|
||||
## Source
|
||||
|
||||
All of Computer Science [http://www.wolframalpha.com/input/?i=base+8](http://www.wolframalpha.com/input/?i=base+8)
|
||||
|
||||
## Submitting Incomplete Problems
|
||||
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|
||||
|
||||
|
|
@ -0,0 +1,24 @@
|
|||
package octal
|
||||
|
||||
import (
|
||||
"errors"
|
||||
"math"
|
||||
)
|
||||
|
||||
// ParseOctal takes a string representation of an octal number
|
||||
// and returns the decimal value of that number, or an error if it
|
||||
// was unparseable as an octal number
|
||||
func ParseOctal(v string) (int64, error) {
|
||||
var ret float64
|
||||
octLen := float64(len(v))
|
||||
for i := range v {
|
||||
octLen--
|
||||
switch {
|
||||
case v[i] > 47 && v[i] < 56:
|
||||
ret = ret + float64(v[i]-48)*math.Pow(8, octLen)
|
||||
default:
|
||||
return 0, errors.New("Unparseable as octal")
|
||||
}
|
||||
}
|
||||
return int64(ret), nil
|
||||
}
|
||||
|
|
@ -0,0 +1,50 @@
|
|||
package octal
|
||||
|
||||
import (
|
||||
"testing"
|
||||
)
|
||||
|
||||
var testCases = []struct {
|
||||
input string
|
||||
expectedNum int64
|
||||
expectErr bool
|
||||
}{
|
||||
{"1", 1, false},
|
||||
{"10", 8, false},
|
||||
{"1234567", 342391, false},
|
||||
{"carrot", 0, true},
|
||||
{"35682", 0, true},
|
||||
}
|
||||
|
||||
func TestParseOctal(t *testing.T) {
|
||||
for _, test := range testCases {
|
||||
actualNum, actualErr := ParseOctal(test.input)
|
||||
if actualNum != test.expectedNum {
|
||||
t.Fatalf("ParseOctal(%s): expected[%d], actual [%d]",
|
||||
test.input, test.expectedNum, actualNum)
|
||||
}
|
||||
|
||||
// if we expect an error and there isn't one
|
||||
if test.expectErr && actualErr == nil {
|
||||
t.Errorf("ParseOctal(%s): expected an error, but error is nil", test.input)
|
||||
}
|
||||
// if we don't expect an error and there is one
|
||||
if !test.expectErr && actualErr != nil {
|
||||
t.Errorf("ParseOctal(%s): expected no error, but error is: %s", test.input, actualErr)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
func BenchmarkParseOctal(b *testing.B) {
|
||||
b.StopTimer()
|
||||
|
||||
for _, test := range testCases {
|
||||
b.StartTimer()
|
||||
|
||||
for i := 0; i < b.N; i++ {
|
||||
ParseOctal(test.input)
|
||||
}
|
||||
|
||||
b.StopTimer()
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,89 @@
|
|||
# Wordy
|
||||
|
||||
Write a program that takes a word problem and returns the answer as an integer.
|
||||
|
||||
## Step 1
|
||||
|
||||
E.g.
|
||||
|
||||
> What is 5 plus 13?
|
||||
|
||||
The program should handle large numbers and negative numbers.
|
||||
|
||||
Remember, that these are verbal word problems, not treated as you
|
||||
normally would treat a written problem. This means that you calculate
|
||||
as you move forward each step. In other words, you should ignore order
|
||||
of operations. 3 + 2 * 3 = 15, not 9.
|
||||
|
||||
Use the tests to drive your solution by deleting the `skip` in one test
|
||||
at a time.
|
||||
|
||||
## Step 2
|
||||
|
||||
E.g.
|
||||
|
||||
> What is 5 plus 13?
|
||||
|
||||
> What is 7 minus 5?
|
||||
|
||||
> What is 6 multiplied by 4?
|
||||
|
||||
> What is 25 divided by 5?
|
||||
|
||||
## Step 3
|
||||
|
||||
E.g.
|
||||
|
||||
> What is 5 plus 13 plus 6?
|
||||
|
||||
> What is 7 minus 5 minus 1?
|
||||
|
||||
> What is 9 minus 3 plus 5?
|
||||
|
||||
> What is 3 plus 5 minus 8?
|
||||
|
||||
## Step 4
|
||||
|
||||
E.g.
|
||||
|
||||
> What is 5 plus 13?
|
||||
|
||||
> What is 7 minus 5?
|
||||
|
||||
> What is 6 times 4?
|
||||
|
||||
> What is 25 divided by 5?
|
||||
|
||||
> What is 78 plus 5 minus 3?
|
||||
|
||||
> What is 18 times 3 plus 16?
|
||||
|
||||
> What is 4 times 3 divided by 6?
|
||||
|
||||
> What is 4 plus 3 times 2?
|
||||
|
||||
## Extensions
|
||||
|
||||
Implement questions of the type:
|
||||
|
||||
> What is 2 raised to the 5th power?
|
||||
|
||||
Remember to write failing tests for this code.
|
||||
|
||||
To run the tests simply run the command `go test` in the exercise directory.
|
||||
|
||||
If the test suite contains benchmarks, you can run these with the `-bench`
|
||||
flag:
|
||||
|
||||
go test -bench .
|
||||
|
||||
For more detailed info about the Go track see the [help
|
||||
page](http://exercism.io/languages/go).
|
||||
|
||||
## Source
|
||||
|
||||
Inspired by one of the generated questions in the Extreme Startup game. [https://github.com/rchatley/extreme_startup](https://github.com/rchatley/extreme_startup)
|
||||
|
||||
## Submitting Incomplete Problems
|
||||
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|
||||
|
||||
|
|
@ -0,0 +1,50 @@
|
|||
package wordy
|
||||
|
||||
import "testing"
|
||||
|
||||
var tests = []struct {
|
||||
q string
|
||||
a int
|
||||
ok bool
|
||||
}{
|
||||
{"What is 1 plus 1?", 2, true},
|
||||
{"What is 53 plus 2?", 55, true},
|
||||
{"What is -1 plus -10?", -11, true},
|
||||
{"What is 123 plus 45678?", 45801, true},
|
||||
{"What is 4 minus -12?", 16, true},
|
||||
{"What is -3 multiplied by 25?", -75, true},
|
||||
{"What is 33 divided by -3?", -11, true},
|
||||
{"What is 1 plus 1 plus 1?", 3, true},
|
||||
{"What is 1 plus 5 minus -2?", 8, true},
|
||||
{"What is 20 minus 4 minus 13?", 3, true},
|
||||
{"What is 17 minus 6 plus 3?", 14, true},
|
||||
{"What is 2 multiplied by -2 multiplied by 3?", -12, true},
|
||||
{"What is -3 plus 7 multiplied by -2?", -8, true},
|
||||
{"What is -12 divided by 2 divided by -3?", 2, true},
|
||||
{"What is 53 cubed?", 0, false},
|
||||
{"Who is the president of the United States?", 0, false},
|
||||
}
|
||||
|
||||
func TestAnswer(t *testing.T) {
|
||||
for _, test := range tests {
|
||||
switch a, ok := Answer(test.q); {
|
||||
case !ok:
|
||||
if test.ok {
|
||||
t.Errorf("Answer(%q) returned ok = false, expecting true.", test.q)
|
||||
}
|
||||
case !test.ok:
|
||||
t.Errorf("Answer(%q) = %d, %t, expecting ok = false.", test.q, a, ok)
|
||||
case a != test.a:
|
||||
t.Errorf("Answer(%q) = %d, want %d.", test.q, a, test.a)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Benchmark combined time to answer all questions.
|
||||
func BenchmarkAnswer(b *testing.B) {
|
||||
for i := 0; i < b.N; i++ {
|
||||
for _, test := range tests {
|
||||
Answer(test.q)
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue