rotate image

Author: zhongn2

Rotate Image.cpp

@@ -0,0 +1,17 @@
+// Rotate 90 degree
+// what about 180 degree?  
+// 1 2 => 4 2 => 3 1
+// 3 4 => 3 1 => 4 2
+class Solution {
+public:
+    void rotate(vector<vector<int> > &matrix) {
+        int n = matrix.size();
+        for(int i = 0; i < n; i++)
+            for(int j = 0; j < n - i; j++)
+                swap(matrix[i][j], matrix[n - 1 - j][n - 1 - i]);
+       
+        for(int i = 0; i < n / 2; i++)
+            for(int j = 0; j < n; j++)
+                swap(matrix[i][j], matrix[n -1 -i][j]);
+    }
+};