[leetcode] 48. Rotate Image

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?

解法一：

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