Added : Two Sum

Author: rohitkumar-rk

LeetCode/Array/1. Two Sum/Problem Statement.txt

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+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].

LeetCode/Array/1. Two Sum/Solution.java

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+/*
+@lc id : 1
+@problem : Two Sum
+@author : rohit
+@url : https://leetcode.com/problems/two-sum/
+*/
+
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        
+        HashMap<Integer, Integer> map = new HashMap<>();
+        
+        for(int i = 0; i < nums.length; i++){
+        
+            if( map.containsKey( target - nums[i] )
+             &&  map.get(target - nums[i]) != i)
+                return new int[]{i, map.get(target - nums[i])};
+            map.put(nums[i], i);
+        }
+        
+        return null;
+    }
+}