@cassidoo mailing list question

binpack.js

// To find the optimal groups we can use bin packing.
// https://en.wikipedia.org/wiki/Bin_packing_problem

const files = [120, 90, 60, 150, 80];
const maxDuration = 200;

function groupAudioFiles(files, maxDuration) {
  // Sort files in descending order
  const sorted = [...files].sort((a, b) => b - a);

  // Track groups of files and their current total durations
  const groups = [];
  const sums = [];

  // Process each file, starting with the largest
  for (const file of sorted) {
    // Index of best fitting group
    let bestIdx = -1;
    // Track minimum remaining space
    let minSpace = maxDuration + 1;

    // Find the group with least remaining space that can still fit this file
    for (let i = 0; i < sums.length; i++) {
      // Remaining capacity
      const space = maxDuration - sums[i]; 
      if (space >= file && space < minSpace) {
        bestIdx = i;
        minSpace = space;
      }
    }

    // Add to best fitting group or create new group if none fit
    bestIdx >= 0
      ? (groups[bestIdx].push(file), (sums[bestIdx] += file))
      : (groups.push([file]), sums.push(file));
  }

  return groups;
}

console.log(groupAudioFiles(files, maxDuration));
console.log(groupAudioFiles(files, 160));