Toeplitz Matrix

Similar Problems:

A matrix is Toeplitz if every diagonal from top-left to bottom-right has the same element.

Now given an M x N matrix, return True if and only if the matrix is Toeplitz.

Example 1:

Input: matrix = [[1,2,3,4],[5,1,2,3],[9,5,1,2]] Output: True Explanation: 1234 5123 9512 In the above grid, the diagonals are "[9]", "[5, 5]", "[1, 1, 1]", "[2, 2, 2]", "[3, 3]", "[4]", and in each diagonal all elements are the same, so the answer is True.

Example 2:

Input: matrix = [[1,2],[2,2]] Output: False Explanation: The diagonal "[1, 2]" has different elements.

Note:

- matrix will be a 2D array of integers.
- matrix will have a number of rows and columns in range [1, 20].
- matrix[i][j] will be integers in range [0, 99].

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

## Blog link: https://code.dennyzhang.com/toeplitz-matrix ## Basic Ideas: Check all m[i][j] with m[i+1][j+1] ## ## (0,0) (1,0) (2,0) (3,0) ## 1 2 3 4 ## 5 1 2 3 ## 9 5 1 2 ## (0,2) (1,2) (2,2) (3,2) ## ## Complexity: Time O(m*n), Space O(1) class Solution(object): def isToeplitzMatrix(self, matrix): """ :type matrix: List[List[int]] :rtype: bool """ row_count = len(matrix) if row_count == 0: return True col_count = len(matrix[0]) for i in xrange(row_count-1): for j in xrange(col_count-1): if matrix[i][j] != matrix[i+1][j+1]: return False return True