Toeplitz Matrix — LeetCode 766 Python Solution

The problem

Given an m x n matrix, return true if the matrix is Toeplitz. Otherwise, return false.

Example

Input

matrix = [[1,2,3,4],[5,1,2,3],[9,5,1,2]]

Output

true

Explanation

In the above grid, the diagonals are:

Python solution

class Solution:
    def isToeplitzMatrix(self, matrix: List[List[int]]) -> bool:
        m, n = len(matrix), len(matrix[0])
        for i in range(1, m):
            for j in range(1, n):
                if matrix[i][j] != matrix[i - 1][j - 1]:
                    return False
        return True

Complexity

Pattern: Matrix and Grid

Treat a 2-D grid as a graph whose neighbours are the four adjacent cells. LeetCode 766. Toeplitz Matrix is filed here on both counts: the reference solution below belongs to the algorithm family this hub collects, and LeetCode tags it Matrix.

The matrix and grid guide has the Python template for the pattern and the 216 LeetCode problems that use it.

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