knapsack.js

function knapsack(vals, wts, maxWeight) {
  var maxValFound = 0;
  
  function maxVal(vals, wts, currentVal, currentWeight) {
    for(var i=0; i<vals.length; i++) {
      var addVal = vals[i];
      var addWeight = wts[i];

      if(currentWeight + addWeight > maxWeight) {
        continue;
      }
      if(currentVal + addVal > maxValFound) {
        maxValFound = currentVal + addVal;
      }

      var newVals = vals.slice();
      newVals.splice(i, 1);
      var newWeights = wts.slice();
      newWeights.splice(i, 1);

      maxVal(newVals, newWeights, currentVal + addVal, currentWeight + addWeight);
    }
  }

  maxVal(vals, wts, 0, 0);

  return maxValFound;
}


maxVal = 1;


vals = [1, 1, 4, 4, 5]
wts = [5, 4, 8, 9, 3]

var x = knapsack(vals, wts, 10);
console.log(x)