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

December LeetCoding Challenge 6

Description

Maximum Number of Integers to Choose From a Range I

You are given an integer array banned and two integers n and maxSum. You are choosing some number of integers following the below rules:

• The chosen integers have to be in the range [1, n].
• Each integer can be chosen at most once.
• The chosen integers should not be in the array banned.
• The sum of the chosen integers should not exceed maxSum.

Return the maximum number of integers you can choose following the mentioned rules.

Example 1:

Input: banned = [1,6,5], n = 5, maxSum = 6
Output: 2
Explanation: You can choose the integers 2 and 4.
2 and 4 are from the range [1, 5], both did not appear in banned, and their sum is 6, which did not exceed maxSum.

Example 2:

Input: banned = [1,2,3,4,5,6,7], n = 8, maxSum = 1
Output: 0
Explanation: You cannot choose any integer while following the mentioned conditions.

Example 3:

Input: banned = [11], n = 7, maxSum = 50
Output: 7
Explanation: You can choose the integers 1, 2, 3, 4, 5, 6, and 7.
They are from the range [1, 7], all did not appear in banned, and their sum is 28, which did not exceed maxSum.

Constraints:

• 1 <= banned.length <= 104
• 1 <= banned[i], n <= 104
• 1 <= maxSum <= 109

Solution

class Solution {
public:
  int maxCount(vector<int>& banned, int n, int maxSum) {
    set<int> blacklist(banned.begin(), banned.end());

    int sum = 0;
    int answer = 0;
    for(int i = 1; i <= n; ++i) {
      if(blacklist.count(i)) continue;
      if(sum + i > maxSum) break;
      sum += i;
      answer += 1;
    }
    return answer;
  }
};

// Accepted
// 208/208 cases passed (287 ms)
// Your runtime beats 22.14 % of cpp submissions
// Your memory usage beats 19.94 % of cpp submissions (185.6 MB)