Update readme.md

Author: javadev

src/main/java/g0001_0100/s0048_rotate_image/readme.md

@@ -26,4 +26,50 @@ You have to rotate the image [**in-place**](https://en.wikipedia.org/wiki/In-pla
 
 *   `n == matrix.length == matrix[i].length`
 *   `1 <= n <= 20`
-*   `-1000 <= matrix[i][j] <= 1000`
+*   `-1000 <= matrix[i][j] <= 1000`
+
+To solve the "Rotate Image" problem in Java with a `Solution` class, we can follow these steps:
+
+1. Define a `Solution` class.
+2. Define a method named `rotate` that takes a 2D array `matrix` representing an image as input and rotates the image by 90 degrees clockwise.
+3. Determine the number of layers in the matrix, which is equal to half of the matrix's size.
+4. Iterate through each layer from outer to inner layers.
+5. For each layer:
+   - Iterate through each element in the current layer.
+   - Swap the elements of the current layer in a clockwise manner.
+6. Return the rotated matrix.
+
+Here's the implementation:
+
+```java
+public class Solution {
+    public void rotate(int[][] matrix) {
+        int n = matrix.length;
+        int layers = n / 2;
+
+        for (int layer = 0; layer < layers; layer++) {
+            int first = layer;
+            int last = n - 1 - layer;
+            
+            for (int i = first; i < last; i++) {
+                int offset = i - first;
+                int top = matrix[first][i];
+                
+                // Move left to top
+                matrix[first][i] = matrix[last - offset][first];
+                
+                // Move bottom to left
+                matrix[last - offset][first] = matrix[last][last - offset];
+                
+                // Move right to bottom
+                matrix[last][last - offset] = matrix[i][last];
+                
+                // Move top to right
+                matrix[i][last] = top;
+            }
+        }
+    }
+}
+```
+
+This implementation provides a solution to the "Rotate Image" problem in Java. It rotates the given 2D matrix representing an image by 90 degrees clockwise in-place.