2020 Day 13 Complete!

helpers/helpers.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"log"
+	"math"
 	"os"
 	"strconv"
 	"strings"
@@ -25,9 +26,11 @@ const (
 
 	MAX_INT = int(^uint(0) >> 1)
 	MIN_INT = -MAX_INT - 1
+
+	SHRUG = "¯\\_(ツ)_/¯"
 )
 
-// Find the greatest common denominator
+// Gcd Finds the greatest common denominator
 func Gcd(x, y int) int {
 	for y != 0 {
 		x, y = y, x%y
@@ -35,7 +38,7 @@ func Gcd(x, y int) int {
 	return x
 }
 
-// Find the least common multiple, using gcd
+// Lcm finds the least common multiple, using gcd
 func Lcm(a, b int, integers ...int) int {
 	result := a * b / Gcd(a, b)
 	for i := 0; i < len(integers); i++ {
@@ -44,6 +47,7 @@ func Lcm(a, b int, integers ...int) int {
 	return result
 }
 
+// AbsInt returns the absolute value of i
 func AbsInt(i int) int {
 	if i < 0 {
 		return i * -1
@@ -51,6 +55,7 @@ func AbsInt(i int) int {
 	return i
 }
 
+// ArgIsSet return true if an argument with the asked for key is present
 func ArgIsSet(a string) bool {
 	for i := range os.Args {
 		if os.Args[i] == a || strings.HasPrefix(os.Args[i], a+"=") {
@@ -60,6 +65,7 @@ func ArgIsSet(a string) bool {
 	return false
 }
 
+// GetArgValue returns the argument with the asked for key or ""
 func GetArgValue(a string) string {
 	for i := range os.Args {
 		if strings.HasPrefix(os.Args[i], a+"=") {
@@ -69,6 +75,7 @@ func GetArgValue(a string) string {
 	return ""
 }
 
+// GetArgNumber returns the asked for argument position or ""
 func GetArgNumber(i int) string {
 	if len(os.Args) > i {
 		return os.Args[i]
@@ -76,6 +83,7 @@ func GetArgNumber(i int) string {
 	return ""
 }
 
+// OptArgNumber returns either the asked for argument position or the passed default
 func OptArgNumber(i int, def string) string {
 	if len(os.Args) > i {
 		return os.Args[i]
@@ -83,6 +91,7 @@ func OptArgNumber(i int, def string) string {
 	return def
 }
 
+// StdinToIntSlice reads from stdin and returns it as an int slice
 func StdinToIntSlice() []int {
 	var ret []int
 	st := StdinToStringSlice()
@@ -92,6 +101,7 @@ func StdinToIntSlice() []int {
 	return ret
 }
 
+// StdinToStringSlice reads from stdin and returns it as a string slice
 func StdinToStringSlice() []string {
 	var input []string
 	scanner := bufio.NewScanner(os.Stdin)
@@ -101,10 +111,12 @@ func StdinToStringSlice() []string {
 	return input
 }
 
+// StdinToCoordMap reads stdin and returns it as a CoordByteMap
 func StdinToCoordMap() CoordByteMap {
 	return StringSliceToCoordByteMap(StdinToStringSlice())
 }
 
+// Atoi is basically redundant
 func Atoi(i string) int {
 	var ret int
 	var err error
@@ -114,10 +126,12 @@ func Atoi(i string) int {
 	return ret
 }
 
+// Itoa is basically redundant
 func Itoa(i int) string {
 	return strconv.Itoa(i)
 }
 
+// StdinToString reads from stdin and returns a string
 func StdinToString() string {
 	var input string
 	scanner := bufio.NewScanner(os.Stdin)
@@ -127,14 +141,17 @@ func StdinToString() string {
 	return input
 }
 
+// FileToStringSlice takes a file and returns it as a slice of strings
 func FileToStringSlice(fn string) []string {
 	return strings.Split(string(FileToBytes(fn)), "\n")
 }
 
+// FileToString reads a file and returns it as a string
 func FileToString(fn string) string {
 	return string(FileToBytes(fn))
 }
 
+// FileToBytes reads a file and returns it as a slice of bytes
 func FileToBytes(fn string) []byte {
 	var c []byte
 	var err error
@@ -146,6 +163,7 @@ func FileToBytes(fn string) []byte {
 	return c
 }
 
+// PrintProgress is for outputting a progress bar
 func PrintProgress(curr, total int) {
 	pct := int(float64(curr)/float64(total)) * 100
 	for i := 0; i < 100; i += 10 {
@@ -155,6 +173,7 @@ func PrintProgress(curr, total int) {
 	}
 }
 
+// StringPermutations takes a string and returns all permutations of it
 func StringPermutations(str string) []string {
 	perms := stringPermHelper(str, 0)
 	var wrk []string
@@ -186,6 +205,7 @@ func stringPermHelper(str string, i int) []string {
 	return ret
 }
 
+// IntPermutations takes a slice of ints and returns all permutations of it
 func IntPermutations(inp []int) [][]int {
 	perms := intPermHelper(inp, 0)
 	var wrk [][]int
@@ -219,6 +239,7 @@ func intPermHelper(inp []int, i int) [][]int {
 	return ret
 }
 
+// IntSlicesAreEqual takes two int slices and returns if they are equal
 func IntSlicesAreEqual(s1 []int, s2 []int) bool {
 	if len(s1) != len(s2) {
 		return false
@@ -231,6 +252,8 @@ func IntSlicesAreEqual(s1 []int, s2 []int) bool {
 	return true
 }
 
+// StringSliceContains takes a string slice and a string and return true
+// if the string is in the slice
 func StringSliceContains(h []string, n string) bool {
 	for _, v := range h {
 		if v == n {
@@ -239,3 +262,13 @@ func StringSliceContains(h []string, n string) bool {
 	}
 	return false
 }
+
+// IsPrime takes a number and return true if that number is prime
+func IsPrime(value int) bool {
+	for i := 2; i <= int(math.Floor(float64(value)/2)); i++ {
+		if value%i == 0 {
+			return false
+		}
+	}
+	return value > 1
+}