3070. Count Submatrices with Top-Left Element and Sum Less Than k
Medium
30 Points
Array
Matrix
Prefix Sum
You are given a 0-indexed integer matrix grid and an integer k.
Return the number of submatrices that contain the top-left element of the grid, and have a sum less than or equal to k.
Examples
Example 1
Input: grid = [[7,6,3],[6,6,1]], k = 18
Output: 4
Explanation: There are only 4 submatrices, shown in the image above, that contain the top-left element of grid, and have a sum less than or equal to 18.
Example 2
Input: grid = [[7,2,9],[1,5,0],[2,6,6]], k = 20
Output: 6
Explanation: There are only 6 submatrices, shown in the image above, that contain the top-left element of grid, and have a sum less than or equal to 20.
Constraints
m == grid.lengthn == grid[i].length1 <= n, m <= 10000 <= grid[i][j] <= 10001 <= k <= 109
3070. Count Submatrices with Top-Left Element and Sum Less Than k
Medium
30 Points
Array
Matrix
Prefix Sum
You are given a 0-indexed integer matrix grid and an integer k.
Return the number of submatrices that contain the top-left element of the grid, and have a sum less than or equal to k.
Examples
Example 1
Input: grid = [[7,6,3],[6,6,1]], k = 18
Output: 4
Explanation: There are only 4 submatrices, shown in the image above, that contain the top-left element of grid, and have a sum less than or equal to 18.
Example 2
Input: grid = [[7,2,9],[1,5,0],[2,6,6]], k = 20
Output: 6
Explanation: There are only 6 submatrices, shown in the image above, that contain the top-left element of grid, and have a sum less than or equal to 20.
Constraints
m == grid.lengthn == grid[i].length1 <= n, m <= 10000 <= grid[i][j] <= 10001 <= k <= 109