Combine AoC Repos

2015/day04/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"crypto/md5"
+	"fmt"
+	"io"
+	"log"
+	"strconv"
+)
+
+func main() {
+	var readInp string
+	for {
+		_, err := fmt.Scan(&readInp)
+		if err != nil {
+			if err != io.EOF {
+				log.Fatal(err)
+			}
+			break
+		}
+	}
+	firstCoin := searchChunk(readInp, 0, 1000000000)
+	fmt.Printf("\n%s%d :: %d\n", readInp, firstCoin, firstCoin)
+}
+
+func searchChunk(key string, start, end int) int {
+	// So we know it's still running
+	for i := start; i <= end; i++ {
+		coin := key + strconv.Itoa(i)
+		coinMd5 := fmt.Sprintf("%x", md5.Sum([]byte(coin)))
+		if isCoin(coinMd5, "000000") {
+			return i
+		}
+	}
+	return -1
+}
+
+func isCoin(s string, moneyMaker string) bool {
+	if len(s) < len(moneyMaker) {
+		return false
+	}
+	for i := 0; i < len(moneyMaker); i++ {
+		if s[i] != moneyMaker[i] {
+			return false
+		}
+	}
+	return true
+}