advent-of-code

commit e6b3b458e6ab8decdef578d6974c0ad85a2c0289
parent 42b3eff19727f550ac0880d36bfa97fe09b9553f
Author: finwo <finwo@pm.me>
Date:   Sun, 11 Dec 2022 16:51:22 +0100

2022/11 solution

Diffstat:
A
2022/day-11/index.js
 | 
107
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
2022/day-11/sample
 | 
28
++++++++++++++++++++++++++++

2 files changed, 135 insertions(+), 0 deletions(-)
diff --git a/2022/day-11/index.js b/2022/day-11/index.js
@@ -0,0 +1,107 @@
+const fs            = require('fs');
+const through       = require('through2');
+const line_for_line = require('../common/line-for-line');
+
+String.prototype.startsWith = function(subject) {
+  return this.substr(0, subject.length) === subject;
+};
+
+const monkeys = [];
+
+fs.createReadStream('input')
+  .pipe(line_for_line())
+
+  // Turn into paragraphs
+  .pipe(through(function(line, enc, cb) {
+    line = line.toString();
+    this.buffer = this.buffer || [];
+
+    // Emit paragraph on empty line
+    if (!line.length) {
+      this.push(this.buffer.join('\n'));
+      this.buffer = [];
+      return cb();
+    }
+
+    // Add line to buffer
+    this.buffer.push(line);
+    cb();
+  }))
+
+  // Prase paragraph
+  .pipe(through(function(paragraph, enc, cb) {
+    paragraph = paragraph.toString();
+
+    const lines = paragraph
+      .split('\n')
+      .map(str => str.replace(/^\s+|\s+$/g, ''))
+      .map(str => str.split(':').map(s => s.replace(/^\s+|\s+$/g, '')))
+      ;
+
+    const monkey = {inspects: 0};
+
+    lines.forEach(line => {
+      const [name, value] = line;
+      if (name.startsWith("Monkey")) {
+        monkey.id = parseInt(name.split(' ').pop());
+      } else if (name == 'Starting items') {
+        monkey.items = value.split(', ').map(v => BigInt(v));
+      } else if (name == 'Test') {
+        monkey.test = BigInt(value.split(' ').pop());
+      } else if (name == 'If true') {
+        monkey.resolve = parseInt(value.split(' ').pop());
+      } else if (name == 'If false') {
+        monkey.reject = parseInt(value.split(' ').pop());
+      } else if (name == 'Operation') {
+        monkey.operation = Function('old', `return ${value.substr(6).replace(/(\d+)/, '$1n')};`);
+      }
+    });
+
+    monkeys.push(monkey);
+    cb();
+  }))
+
+  .on('finish', () => {
+    monkeys.sort((a, b) => a.id - b.id);
+    console.log({ monkeys });
+
+    const pod = monkeys
+      .map(m => m.test)
+      .reduce((r,a) => r*a, 1n);
+
+    for(let i=0; i<10000; i++) {
+
+      for(let j=0; j<monkeys.length; j++) {
+      // for(const monkey of monkeys) {
+        // process.stdout.write(`Monkey ${monkey.id}:\n`);
+        monkeys[j].inspects += monkeys[j].items.length;
+
+        const test = (wl) =>
+          wl % monkeys[j].test == 0n ? monkeys[j].resolve : monkeys[j].reject;
+
+        while(monkeys[j].items.length) {
+          const item = monkeys[j].items.shift();
+          let _new = monkeys[j].operation(item) % pod;
+          monkeys[test(_new)].items.push(_new);
+        }
+        process.stdout.write(`Monkey ${monkeys[j].id} inspected items ${monkeys[j].inspects} times.\n`);
+      }
+      process.stdout.write(`Round ${i} finished\n\n`);
+    }
+
+    // // Find the most active monkeys
+    // for(const monkey of monkeys) {
+    //   process.stdout.write(`Monkey ${monkey.id} inspected items ${monkey.inspects} times.\n`);
+    // }
+
+    monkeys.sort((a, b) => {
+      const x = b.inspects - a.inspects;
+      if (x < 0n) return -1;
+      if (x > 0n) return  1;
+      return 0;
+    });
+
+    process.stdout.write(`\nMonkey business: ${monkeys[0].inspects} * ${monkeys[1].inspects} = ${monkeys[0].inspects * monkeys[1].inspects}\n`);
+
+    console.log('finish');
+  });
diff --git a/2022/day-11/sample b/2022/day-11/sample
@@ -0,0 +1,28 @@
+Monkey 0:
+  Starting items: 79, 98
+  Operation: new = old * 19
+  Test: divisible by 23
+    If true: throw to monkey 2
+    If false: throw to monkey 3
+
+Monkey 1:
+  Starting items: 54, 65, 75, 74
+  Operation: new = old + 6
+  Test: divisible by 19
+    If true: throw to monkey 2
+    If false: throw to monkey 0
+
+Monkey 2:
+  Starting items: 79, 60, 97
+  Operation: new = old * old
+  Test: divisible by 13
+    If true: throw to monkey 1
+    If false: throw to monkey 3
+
+Monkey 3:
+  Starting items: 74
+  Operation: new = old + 3
+  Test: divisible by 17
+    If true: throw to monkey 0
+    If false: throw to monkey 1
+