advent-of-code

Entries to advent of code, multiple years
git clone git://git.finwo.net/misc/advent-of-code
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part-02.ts (2105B)

      1 import { lineByLine } from './line-by-line';
      2 import { weightedValues } from './weighted-values';
      3 import { mostWeightedValue } from './most-weighted-value';
      4 
      5 (async () => {
      6 
      7   // Read whole input into memory this time
      8   const storage = [];
      9   await lineByLine(__dirname + '/input', line => {
     10     if (!line) return;
     11     storage.push(line.split('').map(v => parseInt(v, 2)));
     12   });
     13 
     14   // The things we need to filter
     15   let oxygenReadings   = storage.slice();
     16   let scrubberReadings = storage.slice();
     17 
     18   // Filter the oxygen readings
     19   for(let idx = 0 ; oxygenReadings.length > 1 ; idx++) {
     20     const column     = oxygenReadings.map(a => a[idx]);
     21     const weights    = weightedValues(column);
     22     let   mostCommon = mostWeightedValue(weights, false);
     23 
     24     // Equal = 1, as specified
     25     if (mostCommon === undefined) {
     26       mostCommon = 1;
     27     }
     28 
     29     // Remove non-matching values
     30     oxygenReadings = oxygenReadings.filter(v => v[idx] == mostCommon);
     31   }
     32 
     33   // Filter the scrubber readings
     34   for(let idx = 0 ; scrubberReadings.length > 1 ; idx++) {
     35     const column     = scrubberReadings.map(a => a[idx]);
     36     const weights    = weightedValues(column);
     37     let   mostCommon = mostWeightedValue(weights, false);
     38 
     39     // Equal = 1, as inverted of specified
     40     if (mostCommon === undefined) {
     41       mostCommon = 1;
     42     }
     43 
     44     // Invert, we're working binary-ish
     45     const leastCommon = (!mostCommon) | 0;
     46 
     47     // Remove non-matching values
     48     scrubberReadings = scrubberReadings.filter(v => v[idx] == leastCommon);
     49   }
     50 
     51   // Convert into numbers again
     52   const oxygenRating      = parseInt(oxygenReadings[0].join(''), 2);
     53   const scrubberRating    = parseInt(scrubberReadings[0].join(''), 2);
     54   const lifeSupportRating = oxygenRating * scrubberRating;
     55 
     56   process.stdout.write('\n\n');
     57   process.stdout.write('---[ REPORT ]---\n');
     58   process.stdout.write('\n');
     59   process.stdout.write(`oxygen rating       : ${oxygenRating}\n`);
     60   process.stdout.write(`scrubber rating     : ${scrubberRating}\n`);
     61   process.stdout.write(`life support rating : ${lifeSupportRating}\n`);
     62   process.stdout.write('\n');
     63 
     64 })();
     65