Switching to Python

Hello friends, next few problems will be solved in Python, just to diversify the languages a bit. Starting with basic problems to get a taste of the language: https://leetcode.com/problems/matrix-diagonal-sum/

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

Not much explanation needed for this one, here is the solution, cheers, ACC.

class Solution(object):
    def diagonalSum(self, mat):
        """
        :type mat: List[List[int]]
        :rtype: int
        """
        sum = 0
        for row in range(len(mat)):
            for col in range(len(mat)):
                if row == col or row + col == len(mat) - 1:
                    sum += mat[row][col]

        return sum