Day 5 Complete

day05/input

@@ -0,0 +1 @@
+ojvtpuvg

day05/main.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"bufio"
+	"crypto/md5"
+	"fmt"
+	"log"
+	"math/rand"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+func main() {
+	input := stdinToString()
+	//partOne(input)
+	partTwo(input)
+}
+
+func partOne(input string) {
+	complete := false
+	idx := 1
+	password := ""
+	for !complete {
+		if idx%1000000 == 0 {
+			fmt.Print("O")
+		} else if idx%100000 == 0 {
+			fmt.Print(".")
+		}
+		sum := fmt.Sprintf("%x", md5.Sum([]byte(input+itoa(idx))))
+		if strings.HasPrefix(sum, "00000") {
+			fmt.Println("d")
+			fmt.Println(itoa(idx))
+			password += string(sum[5])
+		}
+		idx++
+		if len(password) == 8 {
+			complete = true
+		}
+	}
+	fmt.Println("")
+	fmt.Println(password)
+}
+
+func partTwo(input string) {
+	fmt.Println("Cracking the Password, hold on to your butts: ")
+	rand.Seed(time.Now().UTC().UnixNano())
+	complete := false
+	idx := 1469580
+	password := []byte{0, 0, 0, 0, 0, 0, 0, 0}
+	printPassword(password)
+	fnd := 0
+	for !complete {
+		sum := fmt.Sprintf("%x", md5.Sum([]byte(input+itoa(idx))))
+		if strings.HasPrefix(sum, "00000") {
+			pos, err := strconv.Atoi(string(sum[5]))
+			if err == nil && pos < 8 && password[pos] == 0 {
+				password[pos] = sum[6]
+				fnd++
+				if fnd == 8 {
+					complete = true
+				}
+			}
+		}
+		if idx%100000 == 0 {
+			clearPassword()
+			printPassword(password)
+		}
+		idx++
+	}
+	clearPassword()
+	printPassword(password)
+	fmt.Println("")
+	fmt.Println("!~CRACK'D~!")
+}
+
+func clearPassword() {
+	fmt.Print("")
+}
+
+func printPassword(pw []byte) {
+	for i := 0; i < len(pw); i++ {
+		if pw[i] == 0 {
+			// Print random char
+			rndBt := byte(97 + rand.Intn(122-97))
+			if rndBt%3 == 0 {
+				fmt.Print(itoa(int(rndBt % 10)))
+			} else {
+				fmt.Print(string(byte(97 + rand.Intn(122-97))))
+			}
+		} else {
+			fmt.Print(string(pw[i]))
+		}
+	}
+}
+
+func stdinToString() string {
+	var input string
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		input = input + scanner.Text()
+	}
+	return input
+}
+
+func itoa(i int) string {
+	return strconv.Itoa(i)
+}
+
+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
+}

day05/problem

@@ -0,0 +1,71 @@
+Advent of Code
+
+--- Day 5: How About a Nice Game of Chess? ---
+
+   You are faced with a security door designed by Easter Bunny engineers that seem to have acquired most of their security knowledge by watching hacking movies.
+
+   The eight-character password for the door is generated one character at a time by finding the MD5 hash of some Door ID (your puzzle input) and an increasing integer
+   index (starting with 0).
+
+   A hash indicates the next character in the password if its hexadecimal representation starts with five zeroes. If it does, the sixth character in the hash is the next
+   character of the password.
+
+   For example, if the Door ID is abc:
+
+     • The first index which produces a hash that starts with five zeroes is 3231929, which we find by hashing abc3231929; the sixth character of the hash, and thus the
+       first character of the password, is 1.
+     • 5017308 produces the next interesting hash, which starts with 000008f82..., so the second character of the password is 8.
+     • The third time a hash starts with five zeroes is for abc5278568, discovering the character f.
+
+   In this example, after continuing this search a total of eight times, the password is 18f47a30.
+
+   Given the actual Door ID, what is the password?
+
+   Your puzzle answer was ________.
+
+--- Part Two ---
+
+   As the door slides open, you are presented with a second door that uses a slightly more inspired security mechanism. Clearly unimpressed by the last version (in what
+   movie is the password decrypted in order?!), the Easter Bunny engineers have worked out a better solution.
+
+   Instead of simply filling in the password from left to right, the hash now also indicates the position within the password to fill. You still look for hashes that begin
+   with five zeroes; however, now, the sixth character represents the position (0-7), and the seventh character is the character to put in that position.
+
+   A hash result of 000001f means that f is the second character in the password. Use only the first result for each position, and ignore invalid positions.
+
+   For example, if the Door ID is abc:
+
+     • The first interesting hash is from abc3231929, which produces 0000015...; so, 5 goes in position 1: _5______.
+     • In the previous method, 5017308 produced an interesting hash; however, it is ignored, because it specifies an invalid position (8).
+     • The second interesting hash is at index 5357525, which produces 000004e...; so, e goes in position 4: _5__e___.
+
+   You almost choke on your popcorn as the final character falls into place, producing the password 05ace8e3.
+
+   Given the actual Door ID and this new method, what is the password? Be extra proud of your solution if it uses a cinematic "decrypting" animation.
+
+   Your puzzle answer was ________.
+
+   Your puzzle input was ojvtpuvg.
+
+References
+
+   Visible links
+   . http://adventofcode.com/
+   . http://adventofcode.com/2016/about
+   . http://adventofcode.com/2016/support
+   . http://adventofcode.com/2016/events
+   . http://adventofcode.com/2016/settings
+   . http://adventofcode.com/2016/auth/logout
+   . http://adventofcode.com/2016
+   . http://adventofcode.com/2016
+   . http://adventofcode.com/2016/leaderboard
+   . http://adventofcode.com/2016/stats
+   . http://adventofcode.com/2016/sponsors
+   . http://adventofcode.com/2016/sponsors
+   . https://www.detroitlabs.com/careers
+   . https://en.wikipedia.org/wiki/Hackers_(film)
+   . https://en.wikipedia.org/wiki/WarGames
+   . https://en.wikipedia.org/wiki/MD5
+   . https://en.wikipedia.org/wiki/Hexadecimal
+   . https://www.youtube.com/watch?v=NHWjlCaIrQo&t=25
+   . http://adventofcode.com/2016