Merge pull request #12 from dieseltravis/day13

Day 13

package.json

@@ -1,6 +1,6 @@
 {
   "name": "meowing-holy-carbon",
-  "version": "2024.12.12",
+  "version": "2024.12.13",
   "description": "Travis's Advent of Code 2024",
   "author": "Travis Hardiman",
   "homepage": "https://github.com/dieseltravis/aoc2024/",

public/funs.js

@@ -993,8 +993,128 @@
       }
     },
     day13: {
-      part1: d => d,
-      part2: d => d
+      part1: (data) => {
+        const matchButtons = /X\+(\d+), Y\+(\d+)/;
+        const matchPrize = /X=(\d+), Y=(\d+)/;
+        let sum = 0;
+        const input = data.trim().split('\n\n').map(r => {
+          const claw = r.split('\n');
+          const buttonA = claw[0].match(matchButtons);
+          const buttonB = claw[1].match(matchButtons);
+          const prize = claw[2].match(matchPrize);
+          const game = {
+            a: {
+              x: +buttonA[1],
+              y: +buttonA[2]
+            },
+            b: {
+              x: +buttonB[1],
+              y: +buttonB[2]
+            },
+            p: {
+              x: +prize[1],
+              y: +prize[2]
+            }
+          };
+          // start at max B value
+          for (let b = 100; b--;) {
+            const bx = b * game.b.x;
+            if (bx <= game.p.x) {
+              const by = b * game.b.y;
+              if (by <= game.p.y) {
+                // remainder after B value
+                const rx = game.p.x - bx;
+                if (rx % game.a.x === 0) {
+                  const ry = game.p.y - by;
+                  if (ry % game.a.y === 0) {
+                    // check A values are equal
+                    const axv = rx / game.a.x;
+                    const ayv = ry / game.a.y;
+                    if (axv === ayv) {
+                      game.p.b = b;
+                      game.p.a = axv;
+                      game.p.t = (axv * 3) + b;
+                      sum += game.p.t;
+                      break;
+                    }
+                  }
+                }
+              }
+            }
+          }
+          return game;
+        });
+        console.log(input, sum);
+        return sum;
+      },
+      part2: (data) => {
+        const matchButtons = /X\+(\d+), Y\+(\d+)/;
+        const matchPrize = /X=(\d+), Y=(\d+)/;
+        const input = data.trim().split('\n\n').map(r => {
+          const claw = r.split('\n');
+          const buttonA = claw[0].match(matchButtons);
+          const buttonB = claw[1].match(matchButtons);
+          const prize = claw[2].match(matchPrize);
+          const game = {
+            a: {
+              x: +buttonA[1],
+              y: +buttonA[2]
+            },
+            b: {
+              x: +buttonB[1],
+              y: +buttonB[2]
+            },
+            p: {
+              x: +prize[1] + 10000000000000,
+              y: +prize[2] + 10000000000000
+            }
+          };
+          return game;
+        });
+        const ymax = input.length;
+        console.log(input, ymax);
+        const sum = input.reduce((acc, game, i) => {
+          // start at max B value
+          const bmax = Math.floor(Math.min(game.p.x / game.b.x, game.p.y / game.b.y)) + 1;
+          const percentage = bmax / 100;
+          let last = bmax;
+          let percent = 100;
+          console.log('processing ' + (i + 1) + ' of ' + ymax + ', counting down from ' + bmax);
+          for (let b = bmax; b--;) {
+            const bx = b * game.b.x;
+            if (bx <= game.p.x) {
+              const by = b * game.b.y;
+              if (by <= game.p.y) {
+                // remainder after B value
+                const rx = game.p.x - bx;
+                if (rx % game.a.x === 0) {
+                  const ry = game.p.y - by;
+                  if (ry % game.a.y === 0) {
+                    // check A values are equal
+                    const axv = rx / game.a.x;
+                    const ayv = ry / game.a.y;
+                    if (axv === ayv) {
+                      game.p.b = b;
+                      game.p.a = axv;
+                      game.p.t = (axv * 3) + b;
+                      acc += game.p.t;
+                      console.log(acc, game.p.t);
+                      break;
+                    }
+                  }
+                }
+              }
+            }
+            if (b < last) {
+              console.log((100 - percent) + '%');
+              last -= percentage;
+              percent--;
+            }
+          }
+          return acc;
+        }, 0);
+        return sum;
+      }
     },
     day14: {
       part1: d => d,

views/index.html

@@ -32,8 +32,8 @@ <h2>solutions:</h2>
         <li><a href="/day/10">day 10</a></li>
         <li><a href="/day/11">day 11</a></li>
         <li><a href="/day/12">day 12</a></li>
+        <li><a href="/day/13">day 13</a> (part 2 very slow)</li>
         <!-- 
-        <li><a href="/day/13">day 13</a></li>
         <li><a href="/day/14">day 14</a></li>
         <li><a href="/day/15">day 15</a></li>
         <li><a href="/day/16">day 16</a></li>