coderbyte.js

/* https://github.com/fay-jai/coderbyte */

function ArrayAdditionI(arr) {
  var arr = arr.sort(function(a, b) { return a-b; })
      max = arr.pop(),
      sums = [];
  (function smash(sum, arr) {
    if(arr.length == 0 || sum > max ) return;
    sums.push(sum)
    for(var i in arr) {
      copy = arr.slice()
      smash(sum+copy.splice(i, 1)[0], copy)
    }
  })(0, arr)
  return sums.indexOf(max) > -1
}

/* test cases */
console.log(
  ArrayAdditionI([4, 6, 23, 10, 1, 3]) == true,
  ArrayAdditionI([3, 5, -1, 8, 12]) == true,
  ArrayAdditionI([1, 2, 3, 100]) == false
)