Combine AoC Repos

2015/day11/input

@@ -0,0 +1 @@
+hepxcrrq

2015/day11/main.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+)
+
+func printUsage() {
+	fmt.Println("Usage: day11 <string> [add-amt]")
+	fmt.Println("If add-amt isn't given, we just add 1")
+	os.Exit(1)
+}
+
+func main() {
+	args := os.Args
+	if len(args) < 2 {
+		printUsage()
+	}
+	var orig string
+	orig = args[1]
+
+	var valid bool
+	for !valid {
+		orig = addOneToString(orig)
+		valid = testPassword(orig)
+	}
+	fmt.Println(orig)
+}
+
+func addOneToString(s string) string {
+	lastPlace := s[len(s)-1]
+	ret := s[:len(s)-1]
+	if lastPlace == 'z' {
+		lastPlace = 'a'
+		ret = addOneToString(s[:len(s)-1])
+	} else {
+		lastPlace++
+	}
+	return ret + string(lastPlace)
+}
+
+func testPassword(s string) bool {
+	if hasValidChars(s) && hasStraight(s) && hasDoubles(s) {
+		return true
+	}
+	return false
+}
+
+// Test if string contains only valid chars
+func hasValidChars(s string) bool {
+	if strings.Count(s, "i") > 0 {
+		return false
+	}
+	if strings.Count(s, "o") > 0 {
+		return false
+	}
+	if strings.Count(s, "l") > 0 {
+		return false
+	}
+	return true
+}
+
+// Test if string has a 3 char straight
+func hasStraight(s string) bool {
+	for i := range s {
+		if i > 1 {
+			if (s[i-2] == s[i]-2) && (s[i-1] == s[i]-1) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// Test if string has 2 doubles
+func hasDoubles(s string) bool {
+	if i := hasDouble(s); i >= 0 {
+		return (hasDouble(s[i+2:]) >= 0)
+	}
+	return false
+}
+
+// Returns index of first double in string
+// -1 if there isn't one
+func hasDouble(s string) int {
+	for i := range s {
+		if i > 0 {
+			if s[i-1] == s[i] {
+				return i - 1
+			}
+		}
+	}
+	return -1
+}

2015/day11/problem

@@ -0,0 +1,75 @@
+                                           Advent of Code
+
+   br0xen 40*
+
+     • [About]
+     • [Stats]
+     • [Leaderboard]
+     • [Settings]
+     • [Log out]
+
+--- Day 11: Corporate Policy ---
+
+   Santa's previous password expired, and he needs help choosing a new one.
+
+   To help him remember his new password after the old one expires, Santa has devised a method of
+   coming up with a password based on the previous one. Corporate policy dictates that passwords
+   must be exactly eight lowercase letters (for security reasons), so he finds his new password by
+   incrementing his old password string repeatedly until it is valid.
+
+   Incrementing is just like counting with numbers: xx, xy, xz, ya, yb, and so on. Increase the
+   rightmost letter one step; if it was z, it wraps around to a, and repeat with the next letter
+   to the left until one doesn't wrap around.
+
+   Unfortunately for Santa, a new Security-Elf recently started, and he has imposed some
+   additional password requirements:
+
+     • Passwords must include one increasing straight of at least three letters, like abc, bcd,
+       cde, and so on, up to xyz. They cannot skip letters; abd doesn't count.
+     • Passwords may not contain the letters i, o, or l, as these letters can be mistaken for
+       other characters and are therefore confusing.
+     • Passwords must contain at least two different, non-overlapping pairs of letters, like aa,
+       bb, or zz.
+
+   For example:
+
+     • hijklmmn meets the first requirement (because it contains the straight hij) but fails the
+       second requirement requirement (because it contains i and l).
+     • abbceffg meets the third requirement (because it repeats bb and ff) but fails the first
+       requirement.
+     • abbcegjk fails the third requirement, because it only has one double letter (bb).
+     • The next password after abcdefgh is abcdffaa.
+     • The next password after ghijklmn is ghjaabcc, because you eventually skip all the passwords
+       that start with ghi..., since i is not allowed.
+
+   Given Santa's current password (your puzzle input), what should his next password be?
+
+   Your puzzle answer was hepxxyzz.
+
+--- Part Two ---
+
+   Santa's password expired again. What's the next one?
+
+   Your puzzle answer was heqaabcc.
+
+   Both parts of this puzzle are complete! They provide two gold stars: **
+
+   At this point, you should return to your advent calendar and try another puzzle.
+
+   Your puzzle input was hepxcrrq.
+
+   You can also [Shareon Twitter Google+ Reddit] this puzzle.
+
+References
+
+   Visible links
+   . http://adventofcode.com/
+   . http://adventofcode.com/about
+   . http://adventofcode.com/stats
+   . http://adventofcode.com/leaderboard
+   . http://adventofcode.com/settings
+   . http://adventofcode.com/auth/logout
+   . http://adventofcode.com/
+   . https://twitter.com/intent/tweet?text=I%27ve+completed+%22Corporate+Policy%22+%2D+Day+11+%2D+Advent+of+Code&url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F11&related=ericwastl&hashtags=AdventOfCode
+   . https://plus.google.com/share?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F11
+   . http://www.reddit.com/submit?url=http%3A%2F%2Fadventofcode%2Ecom%2Fday%2F11&title=I%27ve+completed+%22Corporate+Policy%22+%2D+Day+11+%2D+Advent+of+Code