技術標籤：leetcode演算法leetcode

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

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

Example 1:

Input: matrix = [[1,2,3,4],[5,1,2,3],[9,5,1,2]]
Output: true
Explanation:
In the above grid, the diagonals are:

給一個矩陣，判斷它是不是Toeplitz矩陣
Toeplitz矩陣指每個對角線方向的元素都相等

思路：
對角線方向是指上一個元素是matrix[r][c]，則下一元素是matrix[r+1][c+1]
只需要判斷matrix[r][c] 是否和matrix[r-1][c-1]是否相等即可
0行r和0行的c不需要判斷

public boolean isToeplitzMatrix
 
(int[][] matrix) {
        int m = matrix.length;
        int n = matrix[0].length;
        for(int i = 1; i < m; i++) {
            for(int j = 1; j < n; j++) {
                if(matrix[i][j] != matrix[i-1][j-1]) return false;
            }
        }
        return true;
    }