day14+15

day14/day.go

@@ -0,0 +1,77 @@
+package day14
+
+import (
+	"crypto/md5"
+	"fmt"
+	"strconv"
+	"tools"
+)
+
+func generateHashes(hashmap map[int][]byte, salt string, start, end int, stretch bool) map[int][]byte {
+	for i := start; i <= end; i++ {
+		thisSalt := salt + strconv.Itoa(i)
+		if _, ok := hashmap[i]; ok {
+			continue
+		}
+
+		if !stretch {
+			hashmap[i] = []byte(fmt.Sprintf("%x", md5.Sum([]byte(thisSalt))))
+		} else {
+			hash := fmt.Sprintf("%x", md5.Sum([]byte(thisSalt)))
+			for i := 0; i < 2016; i++ {
+				hash = fmt.Sprintf("%x", md5.Sum([]byte(hash)))
+			}
+			hashmap[i] = []byte(hash)
+		}
+	}
+
+	return hashmap
+}
+
+func getIndexForKeys(salt string, needKeys int, stretch bool) int {
+	hashmap := make(map[int][]byte)
+
+	keyCount := 0
+	index := -1
+	for keyCount < needKeys {
+		index++
+		hashmap = generateHashes(hashmap, salt, index, index+1000, stretch)
+		foundKey := false
+		for i := 0; i < len(hashmap[index])-2; i++ {
+			c := hashmap[index][i]
+			if c == hashmap[index][i+1] && c == hashmap[index][i+2] {
+				for j := 1; j <= 1000; j++ {
+					hash := hashmap[index+j]
+					for k := 1; k < len(hash)-5; k++ {
+						if c != hash[k] {
+							continue
+						}
+						if hash[k+1] == c && hash[k+2] == c && hash[k+3] == c && hash[k+4] == c {
+							foundKey = true
+							keyCount++
+							break
+						}
+					}
+				}
+				break
+			}
+			if foundKey {
+				break
+			}
+		}
+	}
+
+	return index
+}
+
+func Part1(puzzle tools.AoCPuzzle) interface{} {
+	salt := puzzle.GetInputArray()[0]
+
+	return getIndexForKeys(salt, 64, false)
+}
+
+func Part2(puzzle tools.AoCPuzzle) interface{} {
+	salt := puzzle.GetInputArray()[0]
+
+	return getIndexForKeys(salt, 64, true)
+}

day15/day.go

@@ -0,0 +1,70 @@
+package day15
+
+import (
+	"regexp"
+	"strconv"
+	"tools"
+)
+
+type Disc struct {
+	posCount int
+	initPos  int
+}
+
+func parseInput(inp []string, part2 bool) map[int]Disc {
+	discs := make(map[int]Disc)
+	parserRegex := regexp.MustCompile(".*has ([0-9]+) positions.*at position ([0-9]+).")
+	for i, s := range inp {
+		parts := parserRegex.FindStringSubmatch(s)
+		pc, _ := strconv.Atoi(parts[1])
+		ip, _ := strconv.Atoi(parts[2])
+		discs[i] = Disc{pc, ip}
+		if part2 {
+			discs[i+1] = Disc{11, 0}
+		}
+	}
+
+	return discs
+}
+
+func Part1(puzzle tools.AoCPuzzle) interface{} {
+	discs := parseInput(puzzle.GetInputArray(), false)
+
+	tIndex := -1
+	for {
+		tIndex++
+		failed := false
+		for i, d := range discs {
+			if !((d.initPos+tIndex+i+1)%d.posCount == 0) {
+				failed = true
+				break
+			}
+		}
+		if !failed {
+			break
+		}
+	}
+
+	return tIndex
+}
+
+func Part2(puzzle tools.AoCPuzzle) interface{} {
+	discs := parseInput(puzzle.GetInputArray(), true)
+
+	tIndex := -1
+	for {
+		tIndex++
+		failed := false
+		for i, d := range discs {
+			if !((d.initPos+tIndex+i+1)%d.posCount == 0) {
+				failed = true
+				break
+			}
+		}
+		if !failed {
+			break
+		}
+	}
+
+	return tIndex
+}

inputs/14

@@ -0,0 +1 @@
+ahsbgdzn

inputs/14_test

@@ -0,0 +1 @@
+abc

inputs/15

@@ -0,0 +1,6 @@
+Disc #1 has 13 positions; at time=0, it is at position 1.
+Disc #2 has 19 positions; at time=0, it is at position 10.
+Disc #3 has 3 positions; at time=0, it is at position 2.
+Disc #4 has 7 positions; at time=0, it is at position 1.
+Disc #5 has 5 positions; at time=0, it is at position 3.
+Disc #6 has 17 positions; at time=0, it is at position 5.

inputs/15_test

@@ -0,0 +1,2 @@
+Disc #1 has 5 positions; at time=0, it is at position 4.
+Disc #2 has 2 positions; at time=0, it is at position 1.

main.go

@@ -13,6 +13,8 @@ import (
 	"aoc2016/day10"
 	"aoc2016/day12"
 	"aoc2016/day13"
+	"aoc2016/day14"
+	"aoc2016/day15"
 	"flag"
 	"fmt"
 	"os"
@@ -43,8 +45,8 @@ func initDayFunctions() {
 		//		11: {1: day11.Part1, 2: day11.Part2},
 		12: {1: day12.Part1, 2: day12.Part2},
 		13: {1: day13.Part1, 2: day13.Part2},
-		//		14: {1: day14.Part1, 2: day14.Part2},
+		14: {1: day14.Part1, 2: day14.Part2},
-		//		15: {1: day15.Part1, 2: day15.Part2},
+		15: {1: day15.Part1, 2: day15.Part2},
 		//		16: {1: day16.Part1, 2: day16.Part2},
 		//		17: {1: day17.Part1, 2: day17.Part2},
 		//		18: {1: day18.Part1, 2: day18.Part2},