1. Two Sum

1. Two Sum.java

public class Solution {
    public int[] twoSum(int[] nums, int target) {
        int[] res = new int[2];
        
        HashMap<Integer, Integer> map = new HashMap<Integer, Integer>();
        
        for(int i=0;i<nums.length;i++){
            System.out.println(i);
            if(map.get(target-nums[i])!=null){
                res[0] = map.get(target-nums[i]);
                res[1] = i;
                return res;
            }
            
            if(map.get(nums[i])==null){
                map.put(nums[i],i);
            }
        }
        
        return res;
    }
}