Problem
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.
ExampleExample 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.
public class Solution { /** * @param matrix: the given matrix * @return: True if and only if the matrix is Toeplitz */ public boolean isToeplitzMatrix(int[][] matrix) { // Write your code here // DP? No. // New arrays? No. // Why? Because it"s too simple. int m = matrix.length; int n = matrix[0].length; for (int i = 0; i < m; i++) { for (int j = 0; j < n; j++) { if (i == 0 || j == 0) continue; if (matrix[i][j] != matrix[i-1][j-1]) return false; } } return true; } }
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