└── rotate matrix 90 degree


/rotate matrix 90 degree:
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 1 | 
 2 | public class RotateMatrix {
 3 |     public static void main(String[] args) {
 4 |         int[][] matrix = {
 5 |             {1, 2, 3},
 6 |             {4, 5, 6},
 7 |             {7, 8, 9}
 8 |         };
 9 |         
10 |         rotate(matrix);
11 |         
12 |         System.out.println("Rotated Matrix:");
13 |         printMatrix(matrix);
14 |     }
15 |     
16 |     public static void rotate(int[][] matrix) {
17 |         // Transpose the matrix
18 |         int n = matrix.length;
19 |         for (int i = 0; i < n; i++) {
20 |             for (int j = i; j < n; j++) {
21 |                 int temp = matrix[i][j];
22 |                 matrix[i][j] = matrix[j][i];
23 |                 matrix[j][i] = temp;
24 |             }
25 |         }
26 |         
27 |         // Reverse each row
28 |         for (int i = 0; i < n; i++) {
29 |             int left = 0;
30 |             int right = n - 1;
31 |             while (left < right) {
32 |                 int temp = matrix[i][left];
33 |                 matrix[i][left] = matrix[i][right];
34 |                 matrix[i][right] = temp;
35 |                 left++;
36 |                 right--;
37 |             }
38 |         }
39 |     }
40 |     
41 |     public static void printMatrix(int[][] matrix) {
42 |         for (int i = 0; i < matrix.length; i++) {
43 |             for (int j = 0; j < matrix[0].length; j++) {
44 |                 System.out.print(matrix[i][j] + " ");
45 |             }
46 |             System.out.println();
47 |         }
48 |     }
49 | }
50 | 
51 | 
52 | Output:
53 | 
54 | Rotated Matrix:
55 | 7 4 1 
56 | 8 5 2 
57 | 9 6 3
58 | 


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