Bug Report for two-integer-sum

[prem-savla]

Bug Report for https://neetcode.io/problems/two-integer-sum

Please describe the bug below and include any steps to reproduce the bug or screenshots if possible.

The following consists of output from the solution code for the given test case.
public class Solution {
public int[] twoSum(int[] nums, int target) {
HashMap<Integer, Integer> prevMap = new HashMap<>();

    for (int i = 0; i < nums.length; i++) {
        int num = nums[i];
        int diff = target - num;

        if (prevMap.containsKey(diff)) {
            return new int[] { prevMap.get(diff), i };
        }

        prevMap.put(num, i);
    }

    return new int[] {};
}

}

TestCase:
nums=[5,5,5,5,2]
target=7

Your Output:
[3,4]
Expected output:
[3,4]

But the correct answer for this should be the smallest index of integer 5
i.e. [0,4] should be the correct output

Hence adding a - !prevMap.containsKey(num) check before adding num to the prevMap will ensure correctness.

Thank You.