Last updated: Nov 27, 2022
Difficulty : easy
Runtime : 101 ms Faster than 53.01 %
Memory : 44.7 mb Lesser than 13.91 %

1351. 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:

/**
 * @param {number[][]} grid
 * @return {number}
 */

var countNegatives = function(grid) {
    var count = 0;

    for (var arr of grid) {
      for (var i in arr) {
          if(arr[i] < 0) count++;
      }
    }
    return count;
};