2025-07-25 Daily Challenge

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In: DailyChallenge

Today I have done leetcode's July LeetCoding Challenge with cpp.

July LeetCoding Challenge 25

Description

Maximum Unique Subarray Sum After Deletion

You are given an integer array nums.

You are allowed to delete any number of elements from nums without making it empty. After performing the deletions, select a subarray of nums such that:

  1. All elements in the subarray are unique.
  2. The sum of the elements in the subarray is maximized.

Return the maximum sum of such a subarray.

 

Example 1:

Input: nums = [1,2,3,4,5]

Output: 15

Explanation:

Select the entire array without deleting any element to obtain the maximum sum.

Example 2:

Input: nums = [1,1,0,1,1]

Output: 1

Explanation:

Delete the element nums[0] == 1, nums[1] == 1, nums[2] == 0, and nums[3] == 1. Select the entire array [1] to obtain the maximum sum.

Example 3:

Input: nums = [1,2,-1,-2,1,0,-1]

Output: 3

Explanation:

Delete the elements nums[2] == -1 and nums[3] == -2, and select the subarray [2, 1] from [1, 2, 1, 0, -1] to obtain the maximum sum.

 

Constraints:

  • 1 <= nums.length <= 100
  • -100 <= nums[i] <= 100

Solution

class Solution {
public:
  int maxSum(vector<int>& nums) {
    int answer = *max_element(nums.begin(), nums.end());
    if(answer <= 0) return answer;
    answer = 0;
    set<int> have;
    for(auto n : nums) {
      if(n > 0 && !have.count(n)) answer += n;
      have.insert(n);
    }
    return answer;
  }
};

// Accepted
// 927/927 cases passed (3 ms)
// Your runtime beats 25 % of cpp submissions
// Your memory usage beats 23.82 % of cpp submissions (29.7 MB)
Algorithm