Algorithm
Count Submatrices
Solution
class Solution:
def countSubmatrices(self, grid: List[List[int]], k: int) -> int:
n, m = len(grid), len(grid[0])
cols = [0] * m
res = 0
for i in range(n):
row_sum = 0
for j in range(m):
cols[j] += grid[i][j]
row_sum += cols[j]
if row_sum <= k:
res += 1
return resTime Complexity
O(mn)
Space Complexity
O(n)
