Leetcode 1895. Largest Magic Square

2021-07-08 15:54:08 浏览数 (1)

文章作者:Tyan 博客:noahsnail.com | CSDN | 简书

1. Description

2. Solution

**解析:**根据幻方定义,分别检查主对角线、副对角线、各行、各列的和是否相等,按阶次从大到小依次检查,碰到满足条件的返回阶。

  • Version 1
代码语言:javascript复制
class Solution:
    def largestMagicSquare(self, grid: List[List[int]]) -> int:
        m = len(grid)
        n = len(grid[0])
        size = min(m, n)
        for k in range(size, 0, -1):
            for i in range(m-k 1):
                for j in range(n-k 1):
                    if self.check(grid, i, j, k):
                        return k


    def check(self, grid, x, y, k):
        main_diagonal = 0
        secondary_diagonal = 0
        for i in range(k):
            main_diagonal  = grid[x i][y i]
            secondary_diagonal  = grid[x i][y k-i-1]
        if main_diagonal != secondary_diagonal:
            return False

        for i in range(k):
            row = sum(grid[x i][y:y k])
            if row != main_diagonal:
                return False
            column = sum([grid[x j][y i] for j in range(k)])
            if column != main_diagonal:
                return False
        return True

Reference

  1. https://leetcode.com/problems/largest-magic-square/

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