Rotate Image Algorithm
The Rotate Image Algorithm is a widely-used computational technique that involves rotating a given two-dimensional image by a specified angle, usually in a clockwise or counterclockwise direction. This algorithm plays a critical role in various applications, including image processing, computer vision, and graphics, as it assists in adjusting images for better visualization, alignment, or feature extraction. The primary goal of this algorithm is to efficiently reposition the image's pixels while maintaining the original image's aspect ratio and dimensions. Typically, the algorithm can be implemented using several methods, such as matrix manipulation (transposing and reversing), rotation matrix, or specialized image processing libraries.
One common approach to achieve image rotation is by using matrix manipulation, which involves two primary steps - transposing and reversing. During the transposing step, the algorithm swaps the image's rows and columns, essentially making the image's elements mirror along its primary diagonal. Next, in the reversing step, either the rows or columns of the transposed matrix are reversed, depending on the desired rotation direction (clockwise or counterclockwise). For instance, if an image is to be rotated 90 degrees clockwise, the rows of the transposed matrix would be reversed, while for a counterclockwise rotation, the columns would be reversed. This matrix manipulation method ensures that the image is efficiently rotated while preserving its original quality, making it a popular choice for various applications in image processing and computer vision.
class Solution {
public:
void rotate(vector<vector<int>>& matrix) {
// Start typing your C/C++ solution below
// DO NOT write int main() function
int n = matrix.size();
for (int i = 0; i < n / 2; i++) {
for (int j = i; j < n - 1 - i; j++) {
int x = 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] = x;
}
}
}
};
