+
+ 1. Two Sum
+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:
+Input: nums = [3,3], target = 6
+Output: [0,1]Constraints:
+-
+
- 2 <= nums.length <= 10^4 +
- -10^9 <= nums[i] <= 10^9 +
- -10^9 <= target <= 10^9 +
- Only one valid answer exists. +
+
+ var twoSum = function(nums, target) {
+ const map = new Map();
+
+ for (let i = 0; i < nums.length; i++) {
+ const complement = target - nums[i];
+
+ if (map.has(complement)) {
+ return [map.get(complement), i];
+ }
+ map.set(nums[i], i);
+ }
+
+ return [];
+};