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Cut day 17 run time in half

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You'd think I'd have learned my lesson about Dictionaries by now. They're great, but only for sparse input sets or where lookup needs to be as fast as possible and other access types are less important.
This commit is contained in:
Chris Pickett
2021-12-17 11:49:03 -06:00
parent 5189bb6734
commit 8c97fff459
1 changed files with 8 additions and 8 deletions
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16
src/17.cs
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@ -64,26 +64,26 @@ internal class Day17 : Day
return (pt.x, pt.y);
}
private static void Part1(Dictionary<(int x, int y), int> successes)
private static void Part1(List<((int x, int y) pt, int height)> successes)
{
var max = successes.MaxBy(vel => vel.Value);
var numOthers = successes.Count(vel => vel.Value == max.Value);
var max = successes.MaxBy(vel => vel.height);
var numOthers = successes.Count(vel => vel.height == max.height);
Logger.Log($"<+black>> part1: highest Y was at velocity {max.Key} (and {numOthers} other{(numOthers == 1 ? "" : "s")}): <+white>{max.Value}<r>");
Logger.Log($"<+black>> part1: highest Y was at velocity {max.pt} (and {numOthers} other{(numOthers == 1 ? "" : "s")}): <+white>{max.height}<r>");
}
private static void Part2(Dictionary<(int x, int y), int> successes)
private static void Part2(List<((int x, int y) pt, int height)> successes)
{
Logger.Log($"<+black>> part2: #successful velocities: <+white>{successes.Count}<r>");
}
private static Dictionary<(int x, int y), int> GetSuccessfulVelocities(Rectangle bounds)
private static List<((int x, int y) pt, int height)> GetSuccessfulVelocities(Rectangle bounds)
{
var (minX, maxX) = GetXVelocityRange(bounds);
var (minY, maxY) = GetYVelocityRange(bounds);
(int x, int y) pt;
Dictionary<(int x, int y), int> successes = new();
List<((int x, int y) pt, int height)> successes = new();
for (int x = minX; x <= maxX; x++)
{
for (int y = minY; y <= maxY; y++)
@ -103,7 +103,7 @@ internal class Day17 : Day
if (bounds.Contains(pt))
{
successes.Add(startingVelocity, currHighestY);
successes.Add((startingVelocity, currHighestY));
}
}
}