Create 48_Rotate_Image.md

Author: koji

48_Rotate_Image.md

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+## 48. Rotate Image
+
+You are given an n x n 2D matrix representing an image, rotate the image by 90 degrees (clockwise).
+You have to rotate the image in-place, which means you have to modify the input 2D matrix directly. DO NOT allocate another 2D matrix and do the rotation.
+
+
+```
+Input: matrix = [[1,2,3],[4,5,6],[7,8,9]]
+Output: [[7,4,1],[8,5,2],[9,6,3]]
+
+Input: matrix = [[5,1,9,11],[2,4,8,10],[13,3,6,7],[15,14,12,16]]
+Output: [[15,13,2,5],[14,3,4,1],[12,6,8,9],[16,7,10,11]]
+
+Input: matrix = [[1]]
+Output: [[1]]
+
+Input: matrix = [[1,2],[3,4]]
+Output: [[3,1],[4,2]]
+```
+
+Constraints:
+
+matrix.length == n
+matrix[i].length == n
+1 <= n <= 20
+-1000 <= matrix[i][j] <= 1000
+
+
+```python
+for i in range(len(matrix)):
+ for j in range(i, len(matrix)):
+ matrix[i][j],matrix[j][i] = matrix[j][i],matrix[i][j]
+ 
+ 
+ for i in range(len(matrix)):
+ left=0
+ right=len(matrix)-1
+ 
+ while left < right:
+ matrix[i][left], matrix[i][right] = matrix[i][right], matrix[i][left]
+ left+=1
+ right-=1
+```
+
+```
+Runtime: 32 ms, faster than 81.03% of Python3 online submissions for Rotate Image.
+Memory Usage: 14.4 MB, less than 9.01% of Python3 online submissions for Rotate Image.
+```