Matrix rotation, C++ (gcc)

Matrix rotation

//Title of this code

#include <iostream>

using namespace std;

const int n = 4;
const int m = 4;

/*
Rotate by +90:
    Transpose
    Reverse each row

Rotate by -90:
    Transpose
    Reverse each column

Rotate by +180:
    Method 1: Rotate by +90 twice
    Method 2: Reverse each row and then reverse each column

Rotate by -180:
    Method 1: Rotate by -90 twice
    Method 2: Reverse each column and then reverse each row
    Method 3: Reverse by +180 as they are same
*/

void rotateMatrix2(int t[n][m]) {

// transpose
    for (int i = 0; i < n; ++i)
        for (int j = i + 1; j < m; ++j)
            swap(t[i][j], t[j][i]);
 
    // reverse the rows
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m / 2; ++j)
            swap(t[i][j], t[i][m - j - 1]);
}

void rotateMatrix(int t[n][m]) {
    int dest[n][m];
    
    // transpose and reverse but need another matrix
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            dest[j][n - i - 1] = t[i][j];
    
    // copy the matrix
    for (int i = 0; i < n; ++i)
        for (int j = 0; j < m; ++j)
            t[i][j] = dest[i][j];
}

void printMatrix(int t[n][m]) {
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            cout << t[i][j] << " ";
        }
        cout << endl;
    } 
}

int main()
{
    int dest[n][m];
    int t[n][m] = {
                    {5, 1, 2, 6},
                    {1, 1, 9, 3},
                    {1, 1, 2, 3},
                    {8, 1, 2, 7}
                  };
    
    printMatrix(t);
    rotateMatrix2(t);
    //rotateMatrix(t);
    //rotateMatrix2(t);
    //rotateMatrix(t);
    cout << endl;
    printMatrix(t);

}


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