[:solved] #281

Author: ppxyn1

rotate-image/ppxyn1.py

@@ -0,0 +1,32 @@
+# idea: -
+# Time Complexity: O(n^2)
+
+'''
+1 2 3
+4 5 6
+7 8 9
+'''
+class Solution:
+    def rotate(self, matrix: List[List[int]]) -> None:
+        """
+        Do not return anything, modify matrix in-place instead.
+        """
+        n = len(matrix)
+        # Transpose (diagonal elements are fixed)
+        '''
+        1 4 7
+        2 5 8
+        3 6 9
+        '''
+        for i in range(n):
+            for j in range(i+1,n):
+                matrix[i][j] , matrix[j][i] = matrix[j][i], matrix[i][j] 
+        
+        # Reverse each row
+        '''
+        7 4 1
+        8 5 2
+        9 6 3
+        '''
+        for r in matrix:
+            r.reverse()