Two Sum

# Two Sum Given an array of integers `nums` and an integer `target`, return the **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: nums[0] + nums[1] == 9, we return [0, 1]. ``` ## Example 2 ``` Input: nums = [3,2,4], target = 6 Output: [1,2] ``` ## Constraints - `2 <= nums.length <= 10⁴` - `-10⁹ <= nums[i] <= 10⁹` - `-10⁹ <= target <= 10⁹` - **Only one valid answer exists.**