Package g1501_1600.s1572_matrix_diagonal_sum

Class Solution

java.lang.Object

g1501_1600.s1572_matrix_diagonal_sum.Solution

public class Solution
extends Object

1572 - Matrix Diagonal Sum.<p>Easy</p> <p>Given a square matrix <code>mat</code>, return the sum of the matrix diagonals.</p> <p>Only include the sum of all the elements on the primary diagonal and all the elements on the secondary diagonal that are not part of the primary diagonal.</p> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2020/08/14/sample_1911.png" alt="" /></p> <p><strong>Input:</strong> mat = [[<strong>1</strong> ,2, <strong>3</strong> ], [4, <strong>5</strong> ,6], [<strong>7</strong> ,8, <strong>9</strong> ]]</p> <p><strong>Output:</strong> 25</p> <p><strong>Explanation:</strong> Diagonals sum: 1 + 5 + 9 + 3 + 7 = 25 Notice that element mat[1][1] = 5 is counted only once.</p> <p><strong>Example 2:</strong></p> <p><strong>Input:</strong> mat = [[<strong>1</strong> ,1,1, <strong>1</strong> ], [1, <strong>1</strong> , <strong>1</strong> ,1], [1, <strong>1</strong> , <strong>1</strong> ,1], [<strong>1</strong> ,1,1, <strong>1</strong> ]]</p> <p><strong>Output:</strong> 8</p> <p><strong>Example 3:</strong></p> <p><strong>Input:</strong> mat = [[<strong>5</strong> ]]</p> <p><strong>Output:</strong> 5</p> <p><strong>Constraints:</strong></p> <ul> <li><code>n == mat.length == mat[i].length</code></li> <li><code>1 <= n <= 100</code></li> <li><code>1 <= mat[i][j] <= 100</code></li> </ul>

Constructor Summary

Constructors

Constructor	Description
Solution()

Method Summary

Modifier and Type	Method	Description
int	diagonalSum(int[][] mat)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

Solution

public Solution()

Method Details

diagonalSum

public int diagonalSum(int[][] mat)