Added Two Sum problem solution in Java

[Chintha-vardhan]

• Added folder Two_Sum with Solution.java
• Updated index.md with problem link

[github-actions]

👋 @Chintha-vardhan
Thank you for raising your pull request.
Please make sure you have followed our contributing guidelines. We will review it as soon as possible.

[iamwatchdogs]

Please make the suggested changes to approve the PR.

[iamwatchdogs]

Please revert the changes for this file. These changes will be updated automatically by the automation scripts when your PR is successfully merged.

[iamwatchdogs]

It's a good practice to use only imports that are necessary.

Suggested change

	import java.util.*;
	import java.util.HashMap;
	import java.util.Map;

[iamwatchdogs]

Please format your code to pass the linting checks.

Suggested change

	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[]{};
	}
	}
	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[] {};
	}
	}