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]
.
如果数组中每一个对角线上的元素都相等,则返回true
C++(19ms):
1 class Solution { 2 public: 3 bool isToeplitzMatrix(vector<vector<int>>& matrix) { 4 int m = matrix.size() ; 5 int n = matrix[0].size() ; 6 for(int i = 0 ; i < m-1 ; i++){ 7 for(int j = 0 ; j < n-1 ; j++){ 8 if (matrix[i][j] != matrix[i+1][j+1]) 9 return false ; 10 } 11 } 12 return true ; 13 } 14 };