1914. Cyclically Rotating a Grid

You are given an m x n integer matrix grid​​​, where m and n are both even integers, and an integer k.

The matrix is composed of several layers, which is shown in the below image, where each color is its own layer:

A cyclic rotation of the matrix is done by cyclically rotating each layer in the matrix. To cyclically rotate a layer once, each element in the layer will take the place of the adjacent element in the counter-clockwise direction. An example rotation is shown below:

Return the matrix after applying k cyclic rotations to it.

class Solution {
    void internal_swap(vector<vector<int>>& g, int start, int m, int n) {
        for(int i = start; i < n - 1; i++) {
            swap(g[start][i], g[start][i + 1]);
        }
        for(int i = start; i < m - 1; i++) {
            swap(g[i][n - 1], g[i + 1][n - 1]);
        }
        for(int i = n - 1; i > start; i--) {
            swap(g[m - 1][i], g[m - 1][i - 1]);
        }
        for(int i = m - 1; i > start + 1; i--) {
            swap(g[i][start], g[i - 1][start]);
        }
    }
public:
    vector<vector<int>> rotateGrid(vector<vector<int>>& grid, int k) {
        int n = grid.size(), m = grid[0].size();
        for(int i = 0; i < min(m / 2, n / 2); i++) {
            int cnt =              k % (((n - (i * 2)) * 2) + (((m - ((i + 1) * 2))*2)));
            for(int j = 0; j < cnt; j++)
                internal_swap(grid, i, n - i, m - i);
        }
        return grid;
    }
};