Added solution for Leetcode 0048 Rotate Image

Author: frankdavid-bp

problems/01. Arrays/Part 02/01. Leetcode Medium 0048. Rotate Image/Algorithms.md

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+### In-Place Transpose and Reverse Approach
+Transpose the matrix: Convert rows to columns.
+Reverse each row: Swap the elements horizontally.
+
+Time Complexity: O(n{2})
+Space Complexity: O(1)
+
+### In-Place Rotation by Layer
+Approach: Rotate the matrix layer by layer.
+
+Important:
+ The layer-by-layer rotation approach specifically works for 𝑛×𝑛 square matrices. It relies on the symmetry of a square matrix to perform the rotation. For a rectangular matrix (where the number of rows and columns are not equal), this method is not applicable because it will lead to index out-of-bound errors and incorrect rotations.
+
+Steps:
+Iterate over each layer of the matrix from the outermost to the innermost.
+For each layer, rotate the elements in groups of four.
+
+Time Complexity: O(N{2})
+
+Space Complexity: O(1)

problems/01. Arrays/Part 02/01. Leetcode Medium 0048. Rotate Image/java/InPlaceRotationByLayer.java

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+import java.util.Arrays;
+
+public class InPlaceRotationByLayer {
+    public static void main(String[] args) {
+        int[][] nums = {
+            {1,2,3},
+            {4,5,6},
+            {7,8,9}
+        };
+
+        int left = 0;
+        int right = nums.length -1;
+
+        while (left < right) {
+            for(int i = 0; i < (right - left); i++) {
+                int top = left;
+                int bottom = right;
+                // save top left
+                int topLeft = nums[top][left + i];
+
+                // move bottom left to top left
+                nums[top][left + i] = nums[bottom - i][left];
+
+                // move top bottom right to bottom left
+                nums[bottom - i ][left] = nums[bottom][right -i];
+
+                // move top right to bottom right
+                nums[bottom][right - i] = nums[top + i][right];
+
+                // move top left to top right
+                nums[top + i][right] = topLeft;
+            }
+            left++;
+            right--;
+        }
+        System.out.println(Arrays.deepToString(nums));
+    }
+}

problems/01. Arrays/Part 02/01. Leetcode Medium 0048. Rotate Image/java/Solution.java

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+import java.util.Arrays;
+public class TransposeAndReverse {
+    public static void main(String[] args) {
+        int[][] nums = {
+            {1,2,3},
+            {4,5,6},
+            {7,8,9}
+        };
+        
+        int rowLength = nums.length;
+        int colLength = nums[0].length;
+
+        // Transpose the multi-dimensional -> Transpose means simply change row to column and column to row
+        /*{
+            {1,4,7},
+            {2,5,8},
+            {3,6,9}
+          }
+         */
+        for(int i = 0; i < rowLength; i++){
+            for(int j = i+1; j < colLength; j++){
+                int temp = nums[i][j];
+                nums[i][j] = nums[j][i];
+                nums[j][i] = temp;
+            }
+        }     
+        
+        for(int row = 0; row < rowLength; row++){
+            reverse(nums[row]);
+        }
+
+        System.out.println(Arrays.deepToString(nums));
+    }
+
+    private static void reverse(int nums[]){
+        int left = 0;
+        int right = nums.length-1;
+
+        while(left < right){
+            int temp = nums[left];
+            nums[left] = nums[right];
+            nums[right] = temp;
+            left++;
+            right--;
+        }
+    }
+}

problems/01. Arrays/Part 02/01. Leetcode Medium 0048. Rotate Image/java/TransposeAndReverse.java

@@ -1,3 +1,6 @@
+import java.util.HashSet;
+import java.util.Set;
+
 class Solution {
     public int findDuplicate(int[] nums) {
 

problems/01. Arrays/Part 02/04. Leetcode Medium 0287. Find the Duplicate Number/java/Solution.java

@@ -1,3 +1,5 @@
 public class Solution {
+
+    
 
 }