Code Interview – Coderbyte – Array Addition – Code challenge – JavaScript Solution Source Code

function ArrayAddition(arr) { 

// sort the array in ascending order and remove the largest number 
  var target = arr.sort(function(a, b){return a-b}).pop();

  // check if any combination of numbers in the array (excluding the largest number) 
  // can be added up to equal the largest number in the array
  return isContains(arr, target);

  function isContains(arr, target){

  // if the array is empty, check if the target is zero
  if(arr.length === 0){
    return target === 0;
  }

  // get the first element in the array and the remaining elements
  var head = arr[0];
  var tail = arr.slice(1);

  // check if the target can be reached by subtracting the first element from the target
  // and checking if the remaining elements contain a combination that adds up to the result
  // or check if the remaining elements contain a combination that adds up to the target
  return isContains(tail, target - head) || isContains(tail, target);
}

}
   
// keep this function call here 
console.log(ArrayAddition(readline()));