Matrix

int main() {
    std::vector<std::vector<int>> matrix;
    int n, m, element, c1, c2, i, j;
    cin >> n >> m;
    std::vector<int> line;
    for (i = 0; i < n; i++) {
        for (j = 0; j < m; j++) {
            cin >> element;
            line.push_back(element);
        }
        matrix.push_back(line);
        line.clear();
    }
    cin >> c1 >> c2;
    swap_columns(matrix, c1, c2);
    for (i = 0; i < n; i++) {
        for (j = 0; j < m - 1; j++) {
            cout << matrix.at(i).at(j) << " ";
        }
        cout << matrix.at(i).at(j) << "\n";
    }
}