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?
Code:
<span style="font-size:14px;">class Solution {
public:
void rotate(vector<vector<int> > &matrix) {
const int n = matrix.size();
if (n == 0 || n == 1) return;
for (int i = 0; i <= (n-1)/2; ++i)
for (int j = i; j < n-1-i; ++j) {
int temp = matrix[i][j];
matrix[i][j] = 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] = temp;
}
}
};</span>