2026-01-19 09:02:06 +0000 UTC

class Solution:
    def maxSideLength(self, mat: List[List[int]], threshold: int) -> int:
        m, n = len(mat), len(mat[0])
        P = [[0] * (n + 1) for _ in range(m + 1)]
        for i in range(1, m + 1):
            for j in range(1, n + 1):
                P[i][j] = (
                    P[i - 1][j]
                    + P[i][j - 1]
                    - P[i - 1][j - 1]
                    + mat[i - 1][j - 1]
                )

        def getRect(x1, y1, x2, y2):
            return P[x2][y2] - P[x1 - 1][y2] - P[x2][y1 - 1] + P[x1 - 1][y1 - 1]

        r, ans = min(m, n), 0
        for i in range(1, m + 1):
            for j in range(1, n + 1):
                for c in range(ans + 1, r + 1):
                    if (
                        i + c - 1 <= m
                        and j + c - 1 <= n
                        and getRect(i, j, i + c - 1, j + c - 1) <= threshold
                    ):
                        ans += 1
                    else:
                        break
        return ans