Leetcode 1572. Matrix Diagonal Sum

2021-07-27 15:50:20 浏览数 (1)

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

1. Description

2. Solution

**解析:**Version 1,简单根据主对角线和次对角线的位置规律,把对应位置的数加起来即可,如果是奇数行,要考虑中心元素被加了两次,因此要减掉重复相加。

  • Version 1
代码语言:javascript复制
class Solution:
    def diagonalSum(self, mat: List[List[int]]) -> int:
        n = len(mat)
        result = 0
        for i in range(n):
            result  = mat[i][i]
            result  = mat[n-i-1][i]
        if n % 2 == 1:
            mid = n // 2
            result -= mat[mid][mid]
        return result

Reference

  1. https://leetcode.com/problems/matrix-diagonal-sum/

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