leetcode 48

底层搬砖工/readme.txt

@@ -0,0 +1,22 @@
+class Solution(object):
+    def rotate(self, matrix):
+        """
+        :type matrix: List[List[int]]
+        :rtype: void Do not return anything, modify matrix in-place instead.
+        """
+        lens = len(matrix)
+        for x in range(lens):
+            for y in range(lens-x):
+                matrix[x][y],matrix[lens-y-1][lens-x-1] = matrix[lens-y-1][lens-x-1],matrix[x][y]
+        for p in range(lens):
+            for q in range(lens/2):
+                matrix[q][p],matrix[lens-1-q][p] = matrix[lens-1-q][p],matrix[q][p]
+
+
+
+这题考查空间想象，可以想象一个矩阵翻转一个面，然后同时旋转90度，翻转的逆时针90，未翻转的顺时针90
+
+由仿射定理可知这时候将未翻转的翻转过来就是所需的答案。
+
+i,j - 》 （n-1-i,j)->(n-1-j,n-1-i)
+

底层搬砖工/submit.py

@@ -0,0 +1,13 @@
+class Solution(object):
+    def rotate(self, matrix):
+        """
+        :type matrix: List[List[int]]
+        :rtype: void Do not return anything, modify matrix in-place instead.
+        """
+        lens = len(matrix)
+        for x in range(lens):
+            for y in range(lens-x):
+                matrix[x][y],matrix[lens-y-1][lens-x-1] = matrix[lens-y-1][lens-x-1],matrix[x][y]
+        for p in range(lens):
+            for q in range(lens/2):
+                matrix[q][p],matrix[lens-1-q][p] = matrix[lens-1-q][p],matrix[q][p]