|
|
@@ -0,0 +1,184 @@
|
|
|
+using System;
|
|
|
+using System.Collections.Generic;
|
|
|
+using System.IO;
|
|
|
+using System.Linq;
|
|
|
+
|
|
|
+namespace D13._2
|
|
|
+{
|
|
|
+ class Track : Dictionary<(int x, int y), char> { };
|
|
|
+ class Carts : List<(int x, int y, int vx, int vy, int t)> { };
|
|
|
+
|
|
|
+ class Program
|
|
|
+ {
|
|
|
+ static void Main(string[] args)
|
|
|
+ {
|
|
|
+ if (args.Length < 1) return;
|
|
|
+ if (File.Exists(args[0]) == false) return;
|
|
|
+ var file = File.OpenText(args[0]);
|
|
|
+
|
|
|
+ var track = new Track();
|
|
|
+ var carts = new Carts();
|
|
|
+
|
|
|
+ FillTrack(file, track, carts);
|
|
|
+
|
|
|
+ int? last = null;
|
|
|
+ while (last == null)
|
|
|
+ {
|
|
|
+ carts.Sort((a, b) => a.x.CompareTo(b.x));
|
|
|
+ carts.Sort((a, b) => a.y.CompareTo(b.y));
|
|
|
+
|
|
|
+ tick(track, carts);
|
|
|
+
|
|
|
+ last = lastCart(carts);
|
|
|
+ }
|
|
|
+ tick(track, carts);
|
|
|
+
|
|
|
+ var l = carts[last.Value];
|
|
|
+ Console.WriteLine($"The answer is \"{l.x},{l.y}\" ({l.vx},{l.vy})");
|
|
|
+ }
|
|
|
+
|
|
|
+ private static void FillTrack(StreamReader file, Track track, Carts carts)
|
|
|
+ {
|
|
|
+ int y = 0;
|
|
|
+ do
|
|
|
+ {
|
|
|
+ var line = file.ReadLine();
|
|
|
+ if (line == null) break;
|
|
|
+
|
|
|
+ for (int x = 0; x < line.Length; ++x)
|
|
|
+ {
|
|
|
+ char c = line[x];
|
|
|
+ if (c == ' ') continue;
|
|
|
+
|
|
|
+ if (isCart(c))
|
|
|
+ {
|
|
|
+ carts.Add(getCart(c, x, y));
|
|
|
+ c = c == '>' || c == '<' ? '-' : '|';
|
|
|
+ }
|
|
|
+
|
|
|
+ track[(x, y)] = c;
|
|
|
+ }
|
|
|
+
|
|
|
+ y++;
|
|
|
+
|
|
|
+ } while (true);
|
|
|
+ }
|
|
|
+
|
|
|
+ private static void tick(Track track, Carts carts)
|
|
|
+ {
|
|
|
+ for (var i = 0; i < carts.Count; ++i)
|
|
|
+ {
|
|
|
+ var cart = carts[i];
|
|
|
+ if (cart == default) continue;
|
|
|
+
|
|
|
+ cart.x += cart.vx;
|
|
|
+ cart.y += cart.vy;
|
|
|
+
|
|
|
+ if (inter(carts, cart, i)) continue;
|
|
|
+
|
|
|
+ var c = track[(cart.x, cart.y)];
|
|
|
+
|
|
|
+ var ncart = getCart(c, cart);
|
|
|
+ carts[i] = ncart;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ static int? lastCart(Carts carts)
|
|
|
+ {
|
|
|
+ int count = 0;
|
|
|
+ int? cart = null;
|
|
|
+
|
|
|
+ for (var i = 0; i < carts.Count; ++i)
|
|
|
+ {
|
|
|
+ if (carts[i] == default) continue;
|
|
|
+
|
|
|
+ cart = i;
|
|
|
+ count++;
|
|
|
+ }
|
|
|
+ return count == 1 ? cart : null;
|
|
|
+ }
|
|
|
+
|
|
|
+ static bool inter(Carts carts, (int x, int y, int vx, int vy, int t) cj, int skip)
|
|
|
+ {
|
|
|
+ for (var i = 0; i < carts.Count; ++i)
|
|
|
+ {
|
|
|
+ if (i == skip) continue;
|
|
|
+
|
|
|
+ var ci = carts[i];
|
|
|
+ if (ci == default) continue;
|
|
|
+
|
|
|
+ if (ci.x == cj.x && ci.y == cj.y)
|
|
|
+ {
|
|
|
+ carts[i] = default;
|
|
|
+ carts[skip] = default;
|
|
|
+ return true;
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ return false;
|
|
|
+ }
|
|
|
+
|
|
|
+ static bool isCart(char c)
|
|
|
+ {
|
|
|
+ return c == '>' || c == '<' || c == '^' || c == 'v';
|
|
|
+ }
|
|
|
+
|
|
|
+ static (int x, int y, int vx, int vy, int t) getCart(char c, int x, int y)
|
|
|
+ {
|
|
|
+ switch (c)
|
|
|
+ {
|
|
|
+ case '>': return (x, y, +1, +0, 0);
|
|
|
+ case '<': return (x, y, -1, +0, 0);
|
|
|
+ case '^': return (x, y, +0, -1, 0);
|
|
|
+ case 'v': return (x, y, +0, +1, 0);
|
|
|
+ }
|
|
|
+ return default;
|
|
|
+ }
|
|
|
+
|
|
|
+ static (int x, int y, int vx, int vy, int t) getCart(char c, (int x, int y, int vx, int vy, int t) cart)
|
|
|
+ {
|
|
|
+ if (c == '|' || c == '-') return cart;
|
|
|
+ if (c == '+' && cart.t == 1)
|
|
|
+ {
|
|
|
+ cart.t++;
|
|
|
+ return cart;
|
|
|
+ }
|
|
|
+
|
|
|
+ switch (cart)
|
|
|
+ {
|
|
|
+ case var t when t.vx == 1 && t.vy == 0:
|
|
|
+
|
|
|
+ if (c == '/') return (cart.x, cart.y, +0, -1, cart.t);
|
|
|
+ if (c == '\\') return (cart.x, cart.y, +0, +1, cart.t);
|
|
|
+ if (c == '+' && cart.t == 0) return (cart.x, cart.y, +0, -1, 1);
|
|
|
+ if (c == '+' && cart.t == 2) return (cart.x, cart.y, +0, +1, 0);
|
|
|
+ return default;
|
|
|
+
|
|
|
+ case var t when t.vx == -1 && t.vy == 0:
|
|
|
+
|
|
|
+ if (c == '/') return (cart.x, cart.y, +0, +1, cart.t);
|
|
|
+ if (c == '\\') return (cart.x, cart.y, +0, -1, cart.t);
|
|
|
+ if (c == '+' && cart.t == 0) return (cart.x, cart.y, +0, +1, 1);
|
|
|
+ if (c == '+' && cart.t == 2) return (cart.x, cart.y, +0, -1, 0);
|
|
|
+ return default;
|
|
|
+
|
|
|
+ case var t when t.vx == 0 && t.vy == 1:
|
|
|
+
|
|
|
+ if (c == '/') return (cart.x, cart.y, -1, +0, cart.t);
|
|
|
+ if (c == '\\') return (cart.x, cart.y, +1, +0, cart.t);
|
|
|
+ if (c == '+' && cart.t == 0) return (cart.x, cart.y, +1, +0, 1);
|
|
|
+ if (c == '+' && cart.t == 2) return (cart.x, cart.y, -1, +0, 0);
|
|
|
+ return default;
|
|
|
+
|
|
|
+ case var t when t.vx == 0 && t.vy == -1:
|
|
|
+
|
|
|
+ if (c == '/') return (cart.x, cart.y, +1, +0, cart.t);
|
|
|
+ if (c == '\\') return (cart.x, cart.y, -1, +0, cart.t);
|
|
|
+ if (c == '+' && cart.t == 0) return (cart.x, cart.y, -1, +0, 1);
|
|
|
+ if (c == '+' && cart.t == 2) return (cart.x, cart.y, +1, +0, 0);
|
|
|
+ return default;
|
|
|
+ }
|
|
|
+ return default;
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
bastien.monsarrat