Knapsack 0/1 - reverse function that deducts the knapsack content starting from its total value.

KnapsackContents.js

function knapsackContents(items, maxWeight) {
  items = items.sort((a,b)=>a.weight-b.weight);
  var knapsacks = knapsack01(maxWeight, items, true);
  var result = [];
  return contentsHelper(knapsacks, items);
  
  function contentsHelper(matrix, items) {
    var column = matrix[matrix.length-1]
    var numItems = items.length;
    if (numItems === 0) return [];
    var lastBoxInKnapsack = (numItems === 1) ? (column[1] !== 0) : (column[numItems-1] !== column[numItems-2]);
    var boxedResult = lastBoxInKnapsack ? [items[numItems-1]] : [];
    var lastBoxWeight = lastBoxInKnapsack ? items[numItems-1].weight : 0;
    return boxedResult.concat(contentsHelper(matrix.slice(0, matrix.length-lastBoxWeight), items.slice(0, numItems-1)));
  }
}

This function uses my previous gist to analyse the content of a given knapsack.

Sample usage: knapsackContents([{value:1,weight:1},{value:4,weight:3},{value:5,weight:4},{value:7,weight:5}], 8);