Three Sum Problem

In this article, we will be solving another common problem on the array which is the 3 sum problem. Here, we are given an array of N integers and a target integer. We aim to find three elements in the array whose sum equals the target.

Example:

N = 7 

Arr = [12, -1, 2, -3, 1, 0, 6]

Target = 2

Output: Yes

 -1 + 2 + 1 = 2

Solution:

Explanation:

• Our task is to find three numbers in the array whose sum equals to our given target.

• We have used an unordered map to store the elements as we traverse through the array.

• For each pair of elements, we calculate the difference between the target and the current element needed to reach the target sum.

• If the difference is found in the map, it shows that the three numbers sum up to the target is already present, and we return true.

• If no such three numbers are found, then we return false.

Time Complexity: O(N)

Space Complexity: O(N)