feat(2023-20): solve part 2

leyanlo · Dec 20, 2023 · b0c56f2 · b0c56f2
1 parent 67ea4e2
commit b0c56f2
Showing 1 changed file with 98 additions and 7 deletions.
diff --git a/2023/day-20.js b/2023/day-20.js
@@ -11,8 +11,90 @@ var input = `broadcaster -> a
 %b -> con
 &con -> output`;
 var input = readFileSync('./day-20-input.txt', 'utf8').trimEnd();
-// 625185522 too low
+// 239918617350720 too low
 
+// function solve(input) {
+//   // console.log(input);
+//   const map = {};
+//   const initialQueue = [];
+//   for (const line of input.split('\n')) {
+//     let [l, r] = line.split(' -> ');
+//     if (l === 'broadcaster') {
+//       initialQueue.push(
+//         ...r.split(', ').map((module) => ({ module, pulse: 0, from: 'button' }))
+//       );
+//     } else if (l[0] === '%') {
+//       map[l.substring(1)] = {
+//         kind: 'ff',
+//         outputs: r.split(', '),
+//         state: 0,
+//       };
+//     } else {
+//       map[l.substring(1)] = {
+//         kind: 'conj',
+//         outputs: r.split(', '),
+//         inputs: [],
+//       };
+//     }
+//   }
+//
+//   for (const module in map) {
+//     const outputs = map[module].outputs;
+//     for (const output of outputs) {
+//       if (map[output]?.kind === 'conj') {
+//         map[output].inputs.push({ module, state: 0 });
+//       }
+//     }
+//   }
+//   // console.log('map', map);
+//   // console.log('initialQueue', initialQueue);
+//
+//   const nPulses = [0, 0];
+//   for (let i = 0; i < 1000; i++) {
+//     const queue = [...initialQueue];
+//     nPulses[0]++;
+//     while (queue.length) {
+//       const { module, pulse, from } = queue.shift();
+//       nPulses[pulse]++;
+//       const input = map[module];
+//       if (!input) continue;
+//
+//       if (input.kind === 'ff') {
+//         if (!pulse) {
+//           input.state = +!input.state;
+//           queue.push(
+//             ...input.outputs.map((m) => ({
+//               module: m,
+//               pulse: input.state,
+//               from: module,
+//             }))
+//           );
+//         }
+//       } else {
+//         input.inputs = input.inputs.map((i) =>
+//           i.module === from
+//             ? {
+//                 module: from,
+//                 state: pulse,
+//               }
+//             : i
+//         );
+//         queue.push(
+//           ...input.outputs.map((m) => ({
+//             module: m,
+//             pulse: +!input.inputs.every((i) => i.state),
+//             from: module,
+//           }))
+//         );
+//       }
+//     }
+//     // console.log('map', map);
+//     // console.log('nPulses', nPulses);
+//   }
+//   console.log('nPulses', nPulses);
+//   console.log(nPulses[0] * nPulses[1]);
+// }
+// solve(input);
 function solve(input) {
   // console.log(input);
   const map = {};
@@ -49,13 +131,21 @@ function solve(input) {
   // console.log('map', map);
   // console.log('initialQueue', initialQueue);
 
-  const nPulses = [0, 0];
-  for (let i = 0; i < 1000; i++) {
+  // these lead to gq
+  const buttonCounts = {
+    xj: null,
+    qs: null,
+    kz: null,
+    km: null,
+  };
+  let i = 0;
+  while (!Object.values(buttonCounts).every(Boolean)) {
     const queue = [...initialQueue];
-    nPulses[0]++;
     while (queue.length) {
       const { module, pulse, from } = queue.shift();
-      nPulses[pulse]++;
+      if (module in buttonCounts && !pulse) {
+        buttonCounts[module] ||= i;
+      }
       const input = map[module];
       if (!input) continue;
 
@@ -90,8 +180,9 @@ function solve(input) {
     }
     // console.log('map', map);
     // console.log('nPulses', nPulses);
+    i++;
   }
-  console.log('nPulses', nPulses);
-  console.log(nPulses[0] * nPulses[1]);
+  console.log('buttonCounts', buttonCounts);
+  console.log(Object.values(buttonCounts).reduce((acc, n) => acc * (n + 1), 1));
 }
 solve(input);