### Two Sum Problem Java Solution - The Coding Shala

Home >> Interview Questions >> Two Sum Problem

## Two Sum Problem Java Solution

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].

### Two Sum Problem Java Program

Method 1:
We can use HashMap to store value and index.

Java Code:

```class Solution {
public int[] twoSum(int[] nums, int target) {
int[] ans = new int[2];
Map<Integer, Integer> map = new HashMap<Integer, Integer>();
for(int i=0; i<nums.length; i++){
int val = nums[i];
if(map.containsKey(target-val)){
ans[0] = map.get(target-val);
ans[1] = i;
return ans;
}
map.put(val, i);
}
return ans;
}
}
```

Other Posts You May Like
Prev<< Introduction to Array                                                                           NEXT >>Rotate Array