Class Solution

java.lang.Object
g1501_1600.s1572_matrix_diagonal_sum.Solution

public class Solution extends Object
1572 - Matrix Diagonal Sum.

Easy

Given a square matrix mat, return the sum of the matrix diagonals.

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.

Example 1:

Input: mat = [[1 ,2, 3 ], [4, 5 ,6], [7 ,8, 9 ]]

Output: 25

Explanation: Diagonals sum: 1 + 5 + 9 + 3 + 7 = 25 Notice that element mat[1][1] = 5 is counted only once.

Example 2:

Input: mat = [[1 ,1,1, 1 ], [1, 1 , 1 ,1], [1, 1 , 1 ,1], [1 ,1,1, 1 ]]

Output: 8

Example 3:

Input: mat = [[5 ]]

Output: 5

Constraints:

  • n == mat.length == mat[i].length
  • 1 <= n <= 100
  • 1 <= mat[i][j] <= 100
  • Constructor Details Link icon

    • Solution Link icon

      public Solution()
  • Method Details Link icon

    • diagonalSum Link icon

      public int diagonalSum(int[][] mat)