gistfile1.js

//Codilty test for a test scenario on exmaple '(())))(' where example is split at the index K, where K 
//is such that 0 <= K <= N, and N is size of K. At K the number of open
//brackets equals the number of closing brackets

function solution(S) {
    // write your code in JavaScript (Node.js 6.4.0)
    var index, left, right;
    var len = S.length;
    var filter = Array.prototype.filter;
    for (var i = 0; i< len; i++) {
      left = S.slice(0, i);
      right = S.slice(i+1, S.size);
      var leftCount = filter.call(left, (x)=>{
         return x == "(";
      });
      var rightCount = filter.call(right, (x)=>{
         return x == ")";
      });
      if(leftCount.length === rightCount.length) {
        index = i+1;
      }
    }

    return index;
}

var S= "(())))(";
var result = solution(S);
console.log(`index that satisfies solution is: ${result}`);