Package g1501_1600.s1572_matrix_diagonal_sum

Class Solution

java.lang.Object
g1501_1600.s1572_matrix_diagonal_sum.Solution
public class Solution extends java.lang.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 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)