2018 day 14 complete

2018/day14/day14.go

@@ -0,0 +1,95 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var input string
+var recipes []byte
+var elfLocations []int
+
+func main() {
+	input = "290431"
+	if len(os.Args) > 1 {
+		input = os.Args[1]
+	}
+	//part1()
+	part2()
+}
+
+func part1() {
+	fmt.Println("= Part 1 =")
+	elfLocations = []int{0, 1}
+	recipes = []byte{'3', '7'}
+	inp := Atoi(input)
+	for len(recipes) < inp+10 {
+		tick()
+		moveElves()
+	}
+	fmt.Println(string(recipes[inp:]))
+	fmt.Println()
+}
+
+func part2() {
+	fmt.Println("= Part 2 =")
+	elfLocations = []int{0, 1}
+	recipes = []byte{'3', '7'}
+
+	for i := 0; i < 30000000; i++ {
+		tick()
+		moveElves()
+	}
+	fmt.Println(strings.Index(string(recipes), input))
+}
+
+func tick() {
+	r1, r2 := getElfRecipes()
+	//fmt.Println(r1, r2, strconv.Itoa(r1+r2))
+	sum := []byte(strconv.Itoa(int(r1 - '0' + r2 - '0')))
+	recipes = append(recipes, sum...)
+}
+
+func getElfRecipes() (byte, byte) {
+	lgt := len(recipes)
+	if lgt <= elfLocations[0] || lgt <= elfLocations[1] {
+		fmt.Println(elfLocations[0], elfLocations[1], len(recipes))
+		os.Exit(0)
+	}
+	return recipes[elfLocations[0]], recipes[elfLocations[1]]
+}
+
+func moveElves() {
+	for num := range elfLocations {
+		newLoc := (elfLocations[num] + int(recipes[elfLocations[num]]-'0') + 1) % len(recipes)
+		elfLocations[num] = newLoc
+	}
+}
+
+func testForInput() bool {
+	if len(recipes) < len(input) {
+		return false
+	}
+	for i := 0; i < len(input); i++ {
+		idx := len(recipes) - len(input) + i
+		if recipes[idx] != input[i] {
+			return false
+		}
+		//fmt.Println(recipes[idx], "==", inputSlice[i])
+	}
+	idx := len(recipes) - len(input)
+	fmt.Println(recipes[idx:], input)
+	return true
+}
+
+func Atoi(i string) int {
+	var ret int
+	var err error
+	if ret, err = strconv.Atoi(i); err != nil {
+		log.Fatal("Invalid Atoi")
+	}
+	return ret
+}