Suppose we have one n x n 2D matrix. We have to rotate this matrix 90 degrees clockwise. So if the matrix is like-
1 | 5 | 7 |
9 | 6 | 3 |
2 | 1 | 3 |
Then the output will be
2 | 9 | 1 |
1 | 6 | 5 |
3 | 3 | 7 |
To solve this, we will follow these steps −
- Consider temp_mat = [], col := length of matrix – 1
- for col in range 0 to length of matrix
- temp := []
- for row in range length of matrix – 1 down to -1
- add matrix[row, col] in temp
- add temp into temp_mat
- for i in range 0 to length of matrix
- for j in range 0 to length of matrix
- matrix[i, j] := temp_mat[i, j]
- for j in range 0 to length of matrix
Let us see the following implementation to get better understanding −
Example Code (Python)
class Solution(object): def rotate(self, matrix): temp_matrix = [] column = len(matrix)-1 for column in range(len(matrix)): temp = [] for row in range(len(matrix)-1,-1,-1): temp.append(matrix[row][column]) temp_matrix.append(temp) for i in range(len(matrix)): for j in range(len(matrix)): matrix[i][j] = temp_matrix[i][j] return matrix ob1 = Solution() print(ob1.rotate([[1,5,7],[9,6,3],[2,1,3]]))
Input
[[1,5,7],[9,6,3],[2,1,3]]
Output
[[2, 9, 1], [1, 6, 5], [3, 3, 7]]