Rotate matrix by 90 degree (#2316)

Others/RotateMatriceBy90Degree.java

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+package Others;
+
+/**
+ * Given a matrix of size n x n 
+ * We have to rotate this matrix by 90 Degree 
+ * Here is the algorithm for this problem .
+ * 
+ */
+
+import java.util.*;
+
+class Rotate_by_90_degree {
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int t = sc.nextInt();
+
+        while (t-- > 0) {
+            int n = sc.nextInt();
+            int[][] arr = new int[n][n];
+
+            for (int i = 0; i < n; i++)
+                for (int j = 0; j < n; j++)
+                    arr[i][j] = sc.nextInt();
+
+            Rotate g = new Rotate();
+            g.rotate(arr);
+            printMatrix(arr);
+
+        }
+        sc.close();
+    }
+
+    static void printMatrix(int arr[][]) {
+        for (int i = 0; i < arr.length; i++) {
+            for (int j = 0; j < arr[0].length; j++)
+                System.out.print(arr[i][j] + " ");
+            System.out.println("");
+        }
+    }
+}
+
+/**
+ * Class containing the algo to roate matrix by 90 degree 
+ */
+
+class Rotate {
+    static void rotate(int a[][]) {
+        int n = a.length;
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                if (i > j) {
+                    int temp = a[i][j];
+                    a[i][j] = a[j][i];
+                    a[j][i] = temp;
+                }
+            }
+        }
+        int i = 0, k = n - 1;
+        while (i < k) {
+            for (int j = 0; j < n; j++) {
+                int temp = a[i][j];
+                a[i][j] = a[k][j];
+                a[k][j] = temp;
+            }
+
+            i++;
+            k--;
+        }
+
+    }
+}