Added Two Sum problem solution in Java

Author: Chintha-vardhan

Solved-Problems/Two_Sum/Solution.java

@@ -0,0 +1,15 @@
+import java.util.*;
+
+class Solution {
+    public int[] twoSum(int[] nums, int target) {
+        Map<Integer, Integer> map = new HashMap<>();
+        for (int i = 0; i < nums.length; i++) {
+            int complement = target - nums[i];
+            if (map.containsKey(complement)) {
+                return new int[]{map.get(complement), i};
+            }
+            map.put(nums[i], i);
+        }
+        return new int[]{};
+    }
+}

index.md

@@ -10,6 +10,7 @@ Welcome to **Data Structures and Algorithms**, your friendly initiation into the
 	- [Backspace_String_Compare](Solved-Problems/Backspace_String_Compare "goto Backspace_String_Compare")
 	- [Longest_Substring_Without_Repeating_Characters](Solved-Problems/Longest_Substring_Without_Repeating_Characters "goto Longest_Substring_Without_Repeating_Characters")
 	- [Valid_Anagram](Solved-Problems/Valid_Anagram "goto Valid_Anagram")
+  - [Two Sum](./Two_Sum/Solution.java  "goto Two_Sum problem and finding target in an array LeetCode - 1")
 <!-- TABLE OF CONTENT ENDS -->
 
 # Table of Contribution