text: /*
  
  Given an array of integers, return indices of the two numbers such that they add up to a specific target.
  You may assume that each input would have exactly one solution, and you may not use the same element twice.
  
  Example:
    Given nums = [2, 7, 11, 15], target = 9,
    Because nums[0] + nums[1] = 2 + 7 = 9,
    return [0, 1].
  
  */
  
  
  /**
   * @param {number[]} nums
   * @param {number} target
   * @return {number[]}
   */
  var twoSum = function(nums, target) {
      var d = []; // dict
  
      for (var i = 0, l = nums.length; i < l; i++) {
          var two = target - nums[i];
          if ( d[two] !== undefined ) {
              return [ d[two], i ];
          }
          d[ nums[i] ] = i;
      }
  };
  
  
  
  console.log( twoSum([2,7,11,15], 9) );
  