FCC Pairwise

function pairwise(arr, arg) {
  var newarr = arr.slice();
  var sum = 0;

  for (var i = 0; i < newarr.length; i++ ) {
    for (var j = i+1; j < newarr.length; j++) {
      if (newarr[i] + newarr[j] == arg) {
        console.log("values = " + newarr[i] + " + " + newarr[j]);

        var a = newarr.indexOf(newarr[i]);
        var b = newarr.indexOf(newarr[j]);
        sum += a;
        sum += b;
        console.log("indices = " + a + " + " + b);

        newarr[i] = newarr[j] = NaN;


      }
    }
  }
          console.log("END");

  return sum;
}

pairwise([1,4,2,3,0,5], 7);