advent-of-code

commit 0d285583cd7eb162ccef53ae20164af6685ac9d3
parent cff8a8f417c906500cd267920d5934c4b15c60bd
Author: finwo <finwo@pm.me>
Date:   Tue, 13 Dec 2022 12:23:38 +0100

2022/13 solution

Diffstat:
A
2022/common/by-paragraph.js
 | 
24
++++++++++++++++++++++++
A
2022/day-13/index.js
 | 
97
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
2022/day-13/sample
 | 
24
++++++++++++++++++++++++

3 files changed, 145 insertions(+), 0 deletions(-)
diff --git a/2022/common/by-paragraph.js b/2022/common/by-paragraph.js
@@ -0,0 +1,24 @@
+const through       = require('through2');
+const multipipe     = require('multipipe');
+const line_for_line = require('./line-for-line');
+
+module.exports = () =>
+  multipipe(
+    line_for_line(),
+    through.obj(function(line, enc, cb) {
+      line = line.toString();
+      this.buffer = this.buffer || [];
+
+      // Emit paragraph on empty line
+      if (!line.length) {
+        if (this.buffer.length) {
+          this.push(this.buffer.join('\n'));
+        }
+        this.buffer = [];
+        return cb();
+      }
+
+      this.buffer.push(line);
+      cb();
+    })
+  )
diff --git a/2022/day-13/index.js b/2022/day-13/index.js
@@ -0,0 +1,97 @@
+const fs           = require('fs');
+const through      = require('through2');
+const by_paragraph = require('../common/by-paragraph');
+const line_by_line = require('../common/line-for-line');
+
+String.prototype.startsWith = function(subject) {
+  return this.substr(0, subject.length) === subject;
+};
+
+function verify(left, right) {
+  // If both values are 
+  if (
+    ('number' === typeof left) &&
+    ('number' === typeof right)
+  ) {
+    if (left < right) return true;
+    if (left > right) return false;
+  }
+  // If both values are lists, compare values of each list
+  if (
+    Array.isArray(left) &&
+    Array.isArray(right)
+  ) {
+    const len = Math.max(left.length, right.length);
+    for(let i=0; i < len; i++) {
+      if ('undefined' === typeof left[i]) return true;
+      if ('undefined' === typeof right[i]) return false;
+      const result = verify(left[i], right[i]);
+      if ('boolean' === typeof result) return result;
+    }
+  }
+  // If exactly one value is an int, convert the integer to a list and retry
+  if (
+    (Array.isArray(left)) &&
+    ('number' === typeof right)
+  ) {
+    right = [right];
+    return verify(left, right);
+  }
+  if (
+    ('number' === typeof left) &&
+    (Array.isArray(right))
+  ) {
+    left = [left];
+    return verify(left, right);
+  }
+}
+
+let   pairs    = 0;
+let   validSum = 0;
+const dividerA = [[2]];
+const dividerB = [[6]];
+const packets  = [
+  dividerA,
+  dividerB,
+];
+
+fs.createReadStream('input')
+  .pipe(by_paragraph())
+
+  // Minor parsing
+  .pipe(through.obj(function(paragraph, enc, cb) {
+    paragraph = paragraph.toString();
+    this.push(paragraph.split('\n').map(line => JSON.parse(line)));
+    cb();
+  }))
+
+  .pipe(through.obj(function(pair, enc, cb) {
+    const [left, right] = pair;
+
+    const valid = verify(left, right);
+    pairs++;
+    if (valid) validSum += pairs;
+
+    packets.push(left, right);
+
+    console.log(left);
+    console.log(right);
+    console.log(valid);
+    console.log('');
+
+    cb();
+  }))
+
+  .on('finish', () => {
+
+    packets.sort((left, right) => {
+      return verify(left, right) ? -1 : 1;
+    });
+    const idxA = packets.indexOf(dividerA) + 1;
+    const idxB = packets.indexOf(dividerB) + 1;
+    const key  = idxA * idxB;
+
+    console.log(packets);
+    console.log({ validSum, key });
+    console.log('finish');
+  });
diff --git a/2022/day-13/sample b/2022/day-13/sample
@@ -0,0 +1,24 @@
+[1,1,3,1,1]
+[1,1,5,1,1]
+
+[[1],[2,3,4]]
+[[1],4]
+
+[9]
+[[8,7,6]]
+
+[[4,4],4,4]
+[[4,4],4,4,4]
+
+[7,7,7,7]
+[7,7,7]
+
+[]
+[3]
+
+[[[]]]
+[[]]
+
+[1,[2,[3,[4,[5,6,7]]]],8,9]
+[1,[2,[3,[4,[5,6,0]]]],8,9]
+