leetcode

You are given an n x n 2D matrix representing an image.

Rotate the image by 90 degrees (clockwise).

Follow up:
Could you do this in-place?

class Solution {
public:
	void rotate(std::vector<std::vector<int> > &matrix) {
		int n = matrix.size();
		int m = n / 2;         
		for(int i = 0; i < m; i++)
		{
			for(int j = i; j < n - 1 - i; j++)
			{           
				int temp = matrix[j][i];   
				matrix[j][i] = matrix[n - 1 - i][j];
				matrix[n - 1 - i][j] = matrix[n - 1 - j][n - 1 - i];
				matrix[n - 1 - j][n - 1 - i] = matrix[i][n - 1 - j];
				matrix[i][n - 1 - j] = temp;
			}
		}
	}
};


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原文地址:https://www.cnblogs.com/mengfanrong/p/4723122.html