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inline loop
continuous-integration/drone/push Build is passing Details

This commit is contained in:
Ben Harris 2022-12-09 14:26:20 -05:00
parent f45545bed7
commit 8eb033ff4c
1 changed files with 19 additions and 24 deletions
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43
AOC2022/Day09.cs
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@ -11,40 +11,35 @@ public sealed class Day09 : Day
{
}
public override void ProcessInput()
{
public override void ProcessInput() =>
_steps = Input.Select(line => (line[0], int.Parse(line[2..]))).ToList();
}
private int CountTailPositions(int ropeLength)
{
var rope = Enumerable.Range(0, ropeLength).Select(_ => (x: 0, y: 0)).ToArray();
var visited = new HashSet<(int x, int y)>();
foreach (var step in _steps!)
foreach (var step in _steps!.SelectMany(step => Enumerable.Range(0, step.count), (step, _) => step))
{
foreach (var _ in Enumerable.Range(0, step.count))
switch (step.direction)
{
switch (step.direction)
{
case 'U': rope[0].y++; break;
case 'D': rope[0].y--; break;
case 'L': rope[0].x--; break;
case 'R': rope[0].x++; break;
}
foreach (var i in Enumerable.Range(1, ropeLength - 1))
{
int dx = rope[i - 1].x - rope[i].x, dy = rope[i - 1].y - rope[i].y;
if (Math.Max(Math.Abs(dx), Math.Abs(dy)) > 1)
{
rope[i].x += Math.Sign(dx);
rope[i].y += Math.Sign(dy);
}
}
visited.Add(rope.Last());
case 'U': rope[0].y++; break;
case 'D': rope[0].y--; break;
case 'L': rope[0].x--; break;
case 'R': rope[0].x++; break;
}
foreach (var i in Enumerable.Range(1, ropeLength - 1))
{
int dx = rope[i - 1].x - rope[i].x, dy = rope[i - 1].y - rope[i].y;
if (Math.Max(Math.Abs(dx), Math.Abs(dy)) > 1)
{
rope[i].x += Math.Sign(dx);
rope[i].y += Math.Sign(dy);
}
}
visited.Add(rope.Last());
}
return visited.Count;