83 lines
1.6 KiB
Go
83 lines
1.6 KiB
Go
package main
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import (
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"crypto/md5"
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"fmt"
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"log"
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"os"
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"strconv"
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"strings"
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)
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var hashStore []string
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var salt string
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func main() {
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if len(os.Args) < 3 {
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fmt.Println("Usage: ./day14 <salt> <key-num>")
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fmt.Println(" My input: ./day14 cuanljph 64")
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os.Exit(1)
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}
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salt = os.Args[1]
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keyNum := atoi(os.Args[2])
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var foundKeys []string
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tryIdx := 0
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for len(foundKeys) < keyNum {
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tst := getHash(tryIdx)
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for i := range tst {
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if len(tst) > i+3 {
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if tst[i:i+3] == strings.Repeat(string(tst[i]), 3) {
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// Found a triple, search the next 1000 for a quintuple
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if searchForQuint(salt, tryIdx+1, string(tst[i])) {
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foundKeys = append(foundKeys, tst)
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}
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// Once we test the first triplet, we're done with this one
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break
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}
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}
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}
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tryIdx++
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}
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fmt.Println("Key:", getHash(tryIdx-1), "Idx:", tryIdx)
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}
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func getHash(idx int) string {
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for len(hashStore)-1 < idx {
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hashStore = append(
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hashStore,
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getStretchedHash(fmt.Sprintf("%x", md5.Sum([]byte(salt+itoa(len(hashStore)+1))))),
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)
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}
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return hashStore[idx]
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}
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func getStretchedHash(s string) string {
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for i := 0; i < 2016; i++ {
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s = fmt.Sprintf("%x", md5.Sum([]byte(s)))
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}
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return s
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}
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func searchForQuint(salt string, startIdx int, srch string) bool {
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for i := startIdx; i <= startIdx+1000; i++ {
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tst := getHash(i)
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if strings.Contains(tst, strings.Repeat(srch, 5)) {
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return true
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}
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}
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return false
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}
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func atoi(i string) int {
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var ret int
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var err error
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if ret, err = strconv.Atoi(i); err != nil {
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log.Fatal("Invalid Atoi")
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}
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return ret
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}
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func itoa(i int) string {
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return strconv.Itoa(i)
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}
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