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

June LeetCoding Challenge 8

Description

Count Negative Numbers in a Sorted Matrix

Given a m x n matrix grid which is sorted in non-increasing order both row-wise and column-wise, return the number of negative numbers in grid.

Example 1:

Input: grid = [[4,3,2,-1],[3,2,1,-1],[1,1,-1,-2],[-1,-1,-2,-3]]
Output: 8
Explanation: There are 8 negatives number in the matrix.

Example 2:

Input: grid = [[3,2],[1,0]]
Output: 0

Constraints:

• m == grid.length
• n == grid[i].length
• 1 <= m, n <= 100
• -100 <= grid[i][j] <= 100

Solution

class Solution {
public:
  int countNegatives(vector<vector<int>>& grid) {
    int answer = 0;
    for(auto &row : grid) {
      for(auto i : row) {
        answer += i < 0;
      }
    }
    return answer;
  }
};

// Accepted
// 44/44 cases passed (19 ms)
// Your runtime beats 43.59 % of cpp submissions
// Your memory usage beats 71.33 % of cpp submissions (10.4 MB)