Two Sum

Description

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].

Solution(javascript)

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
var twoSum = function(nums, target) {
  var map = new Map();
  var len = nums.length;
  
  for(var i = 0; i < len; i++){
      var num = nums[i];
      var complement = target - num;
      if(map.has(complement)){
         return [map.get(complement), i];
      } else {
        map.set(num, i);
      }
  }
};