add: two sum

LeetcodeProblems/Algorithms/2Sum.js

@@ -0,0 +1,43 @@
+/**
+2 Sum
+https://leetcode.com/problems/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]
+
+*/
+
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+ var twoSum = function(nums, target) {
+  let map ={};
+  for(let i=0;i<nums.length;i++){
+      const sum = target-nums[i];
+      if(map[parseInt(sum)] != void 0){
+          return [map[sum], i];
+      } else{
+          map[nums[i]] = i;
+      }
+  }
+};
+
+module.exports.twoSum = twoSum;

README.md

@@ -76,6 +76,7 @@ To run a specific problem in your console run  `node <problem_file_path>` (e.g.
 | [Binary Gap ](/LeetcodeProblems/Algorithms/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
 | [Binary Gap ](/LeetcodeProblems/Algorithms/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
 | [Majority Element](/LeetcodeProblems/Algorithms/Majority_Element.js)                                            | Easy   | https://leetcode.com/problems/majority-element/ |
+| [Two Sum](/LeetcodeProblems/Algorithms/2Sum.js)                                            | Easy   | https://leetcode.com/problems/two-sum/ |
 | [Tic Tac Toe ](/LeetcodeProblems/Algorithms/Tic_Tac_Toe.js)                                                     |        | |
 | [Permutations With Duplicates ](/LeetcodeProblems/Algorithms/Permutations_With_Duplicates.js)                   |        | |
 | [Deletion Distance](/LeetcodeProblems/Algorithms/Deletion_Distance.js)                                          |        | |