43 lines
999 B
C#
43 lines
999 B
C#
using System.Security.Cryptography;
|
|
|
|
namespace AOC2015;
|
|
|
|
/// <summary>
|
|
/// Day 4: <a href="https://adventofcode.com/2015/day/4"/>
|
|
/// </summary>
|
|
public sealed class Day04() : Day(2015, 4, "The Ideal Stocking Stuffer")
|
|
{
|
|
private string? _key;
|
|
|
|
public override void ProcessInput()
|
|
{
|
|
_key = Input.First();
|
|
}
|
|
|
|
public override object Part1()
|
|
{
|
|
var counter = 0;
|
|
|
|
while (true)
|
|
{
|
|
var hash = MD5.HashData(Encoding.ASCII.GetBytes(_key + counter));
|
|
if (BitConverter.ToString(hash).Replace("-", "").StartsWith("00000"))
|
|
return counter;
|
|
counter++;
|
|
}
|
|
}
|
|
|
|
public override object Part2()
|
|
{
|
|
var counter = 9_000_000;
|
|
|
|
while (true)
|
|
{
|
|
var hashBytes = MD5.HashData(Encoding.ASCII.GetBytes(_key + counter));
|
|
if (hashBytes[0] == 0 && hashBytes[1] == 0 && hashBytes[2] == 0)
|
|
return counter;
|
|
counter++;
|
|
}
|
|
}
|
|
}
|