advent-of-code

commit 1a8e4c43e5637684036883f481ca802341bb5ba2
parent 3eefdb2273f806d24906a42adde838478009e9ac
Author: finwo <finwo@pm.me>
Date:   Wed, 24 Dec 2025 18:26:51 +0100

2025/05 half-done

Diffstat:
A
2025/05/example.txt
 | 
11
+++++++++++
A
2025/05/index.js
 | 
84
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 95 insertions(+), 0 deletions(-)
diff --git a/2025/05/example.txt b/2025/05/example.txt
@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32
diff --git a/2025/05/index.js b/2025/05/index.js
@@ -0,0 +1,84 @@
+#!/usr/bin/env node
+
+const fs = require('node:fs');
+
+const [rawRanges, rawQueries] = fs
+  .readFileSync('input', 'utf-8')
+  .split('\r\n').join('\n')
+  .split('\r').join('\n')
+  .split('\n\n');
+
+const ranges = rawRanges
+  .split('\n')
+  .filter(line => line)
+  .map(line => line.split('-').map(n => BigInt(n)))
+  .map(range => ({ start: range[0], end: range[1] }))
+;
+
+const queries = rawQueries
+  .split('\n')
+  .filter(line => line)
+  .map(line => BigInt(line))
+;
+
+const compositeRanges = ranges.map(range => ({...range}));
+for(let i = 0; i < compositeRanges.length; i++) {
+  const range = compositeRanges[i];
+
+  // Find the first range this low one matches
+  const foundLow = compositeRanges.find(({start,end}) => {
+    if (range.start < start) return false;
+    if (range.start > end  ) return false;
+    return true;
+  });
+  const foundLowIndex = compositeRanges.indexOf(foundLow);
+
+  // Merge with low range
+  if (i !== foundLowIndex) {
+    process.stdout.write(`Merging ${foundLow.start}-${foundLow.end},${range.start}-${range.end} => `);
+    range.start = foundLow.start < range.start ? foundLow.start : range.start;
+    range.end   = foundLow.end   > range.end   ? foundLow.end   : range.end  ;
+    process.stdout.write(`${range.start}-${range.end}\n`);
+    compositeRanges.splice(foundLowIndex, 1);
+    i = -1;
+    continue;
+  }
+
+  // Find the first range this high one matches
+  const foundHigh = compositeRanges.find(({start,end}) => {
+    if (range.end < start) return false;
+    if (range.end > end  ) return false;
+    return true;
+  });
+  const foundHighIndex = compositeRanges.indexOf(foundHigh);
+
+  // Merge with high range
+  if (i !== foundHighIndex) {
+    process.stdout.write(`Merging ${foundHigh.start}-${foundHigh.end},${range.start}-${range.end} => `);
+    range.start = foundHigh.start < range.start ? foundHigh.start : range.start;
+    range.end   = foundHigh.end   > range.end   ? foundHigh.end   : range.end  ;
+    process.stdout.write(`${range.start}-${range.end}\n`);
+    compositeRanges.splice(foundHighIndex, 1);
+    i = -1;
+    continue;
+  }
+}
+
+const part1 = queries
+  .filter(ingredientId => compositeRanges.find(({start,end}) => {
+    if (ingredientId < start) return false;
+    if (ingredientId > end  ) return false;
+    return true;
+  }))
+  .length;
+
+const part2 = compositeRanges
+  .map(range => `${range.start}-${range.end} => ${range.end - range.start + 1n}`)
+  // .map(range => (range.end - range.start + 1n))
+  // .reduce((r,a) => r+a, 0n)
+
+console.log(part2.join('\n'));
+
+process.stdout.write(`------[ Part 1: ${part1} ]------\n`);
+process.stdout.write(`------[ Part 2: ${part2} ]------\n`);
+