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Day 22. Finally kinda happy with this one, copied code notwithstanding

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This commit is contained in:
Chris Pickett
2020-12-22 00:28:17 -06:00
parent b9d9ee8dca
commit 1b0e401e03
4 changed files with 215 additions and 0 deletions
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3
2020.csproj
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@ -65,6 +65,9 @@
<None Update="21input.txt">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>
<None Update="22input.txt">
<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
</None>
</ItemGroup>
</Project>

53
22input.txt Normal file
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@ -0,0 +1,53 @@
Player 1:
8
19
46
11
36
10
35
9
24
22
50
1
34
7
18
28
3
38
43
2
6
42
23
12
20
Player 2:
39
27
44
29
5
48
30
32
15
31
14
21
49
17
45
47
16
26
33
25
13
41
4
40
37

1
Program.cs
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@ -23,6 +23,7 @@
Q18.Go();
Q19.Go();
Q21.Go();
Q22.Go();
Util.Log($"Total time={(System.DateTime.Now - start).TotalMilliseconds}ms");
}
}

158
Q22.cs Normal file
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@ -0,0 +1,158 @@
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
namespace _2020
{
class Q22
{
static Dictionary<int, List<int>> list = new Dictionary<int, List<int>>();
public static void Go()
{
var start = DateTime.Now;
MakeList();
Util.Log($"Q22 MakeList took {(DateTime.Now - start).TotalMilliseconds}ms");
var p1start = DateTime.Now;
Part1();
Util.Log($"Q22 part1 took {(DateTime.Now - p1start).TotalMilliseconds}ms");
var p2start = DateTime.Now;
Part2();
Util.Log($"Q22 part2 took {(DateTime.Now - p2start).TotalMilliseconds}ms");
Util.Log($"Q22 took {(DateTime.Now - start).TotalMilliseconds}ms");
}
static void MakeList()
{
var currPlayer = 0;
foreach (var line in File.ReadAllLines("22input.txt"))
{
if (line.StartsWith("Player "))
{
currPlayer = Convert.ToInt32(line["Player ".Length..^1]);
list.Add(currPlayer, new List<int>());
}
else if (string.IsNullOrWhiteSpace(line))
{
continue;
}
else
{
list[currPlayer].Add(Convert.ToInt32(line));
}
}
}
static void Part1()
{
var p1deck = new List<int>(list[1]);
var p2deck = new List<int>(list[2]);
while (p1deck.Any() && p2deck.Any())
{
var p1card = p1deck.First();
p1deck.RemoveAt(0);
var p2card = p2deck.First();
p2deck.RemoveAt(0);
if (p1card > p2card)
{
p1deck.Add(p1card);
p1deck.Add(p2card);
}
else
{
p2deck.Add(p2card);
p2deck.Add(p1card);
}
}
var winner = p1deck.Count == 0 ? p2deck : p1deck;
var score = 0;
for (int i = winner.Count - 1; i >= 0; i--)
{
score += (i + 1) * winner[winner.Count - i - 1];
}
Util.Log($"Q22Part1: score={score}");
}
static int gameNum = 0;
static int deepestLevel = 0;
static int currLevel = 0;
static int PlayRecursiveGame(List<int> p1deck, List<int> p2deck)
{
gameNum++;
currLevel++;
if (currLevel > deepestLevel)
{
deepestLevel = currLevel;
}
var p1prev = new List<List<int>>();
var p2prev = new List<List<int>>();
while (p1deck.Any() && p2deck.Any())
{
if (p1prev.Any(x => Enumerable.SequenceEqual(p1deck, x)) && p2prev.Any(x => Enumerable.SequenceEqual(p2deck, x)))
{
currLevel--;
return 1;
}
p1prev.Add(new List<int>(p1deck));
p2prev.Add(new List<int>(p2deck));
var p1card = p1deck.First();
p1deck.RemoveAt(0);
var p2card = p2deck.First();
p2deck.RemoveAt(0);
if (p1deck.Count >= p1card && p2deck.Count >= p2card)
{
var winner = PlayRecursiveGame(new List<int>(p1deck.Take(p1card)), new List<int>(p2deck.Take(p2card)));
if (winner == 1)
{
p1deck.Add(p1card);
p1deck.Add(p2card);
}
else
{
p2deck.Add(p2card);
p2deck.Add(p1card);
}
}
else
{
if (p1card > p2card)
{
p1deck.Add(p1card);
p1deck.Add(p2card);
}
else
{
p2deck.Add(p2card);
p2deck.Add(p1card);
}
}
}
currLevel--;
return p1deck.Any() ? 1 : 2;
}
static void Part2()
{
var winner = PlayRecursiveGame(list[1], list[2]);
var score = 0;
var winnerDeck = list[winner];
for (int i = winnerDeck.Count - 1; i >= 0; i--)
{
score += (i + 1) * winnerDeck[winnerDeck.Count - i - 1];
}
Util.Log($"Q22Part2: games played={gameNum}, deepest level={deepestLevel}, score={score}");
}
}
}