48. Rotate Image

题目来源：

https://leetcode.com/problems/rotate-image/

自我感觉难度/真实难度：hard 写题时间时长：1h

题意：

旋转一个矩阵

分析：

我自己打算用旋转最外圈的元素来实现旋转，内圈也是。但是这样很容易出错，对圈数和行数之间的关系，很容易出错

自己的代码：

class Solution:
    def rotate(self, m: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        length=len(m)
        n_loop=length//2
        for i in range(n_loop):
            new_len=length-i*2
            for _ in range(1,new_len-1):
                templ=m[i][i]
                for j in range(1,new_len):
                    m[i+j-1][i]=m[i+j][i]
                for j in range(1,new_len):
                    m[length-i-1][i+j-1]=m[length-i-1][i+j]
                for j in range(1,new_len):
                    m[length-i-j][length-i-1]=m[length-i-j-1][length-i-1]
                for j in range(1,new_len):
                    m[i][length-i-j]=m[i][length-i-j-1]
                m[i][i+1]=templ
        return

代码效率/结果：

优秀代码：

class Solution:
    def rotate(self, A):
        A.reverse()
        for i in range(len(A)):
            for j in range(i):
                A[i][j], A[j][i] = A[j][i], A[i][j]

代码效率/结果：

自己优化后的代码：

class Solution:
    def rotate(self, m: List[List[int]]) -> None:
        """
        Do not return anything, modify matrix in-place instead.
        """
        length=len(m)
        n_loop=length//2
        for i in range(n_loop):
            m[i],m[length-1-i]=m[length-1-i],m[i]
        for row in range(length):
            for colum in range(row,length):
                m[row][colum],m[colum][row]=m[colum][row],m[row][colum]  
        return