//Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target. //You may assume that each input would have exactly one solution, and you may not use the same element twice. //You can return the answer in any order. /*Example 1: Input: nums = [2,7,11,15], target = 9 Output: [0,1] Explanation: Because nums[0] + nums[1] == 9, we return [0, 1]. Example 2: Input: nums = [3,2,4], target = 6 Output: [1,2] Example 3: