48. Rotate Image

Here is my second practice in 2017.

I will write down my understanding, and highlight my solution in short future. Stay tuned.

public class Solution {
    public void Rotate(int[,] matrix) {
        int rows = matrix.GetLength(0); 
            int cols = matrix.GetLength(1); 
            
            int index = 0;
            while (2 * index < rows )
            {
                reverseRows(index, rows - 1 - index, matrix);
                index++; 
            }

            for (int row = 0; row < rows; ++row) 
            {
                for (int col = row + 1; col < cols; ++col)
                {
                    swap(row, col, matrix);
                }
            }
    }
    
     private  void reverseRows(int row1, int row2, int[,] matrix)
        {
            int cols = matrix.GetLength(1);
            for (int col = 0; col < cols; col++)
            {
                int tmp = matrix[row1, col];
                matrix[row1, col] = matrix[row2, col];
                matrix[row2, col] = tmp; 
            }
        }

        private  void swap(int row, int col, int[,] matrix)
        {
            int tmp = matrix[row, col];
            matrix[row, col] = matrix[col, row];
            matrix[col, row] = tmp; 
        }
}