function selected_parents = tournament_selection(population, fitness, n)
    selected_parents = zeros(n, size(population, 2));
    for i = 1:n
        %randomly select 2 indiviuals
        idx = randi([1, size(population, 1)], 2, 1);
        if fitness(idx(1)) > fitness(idx(2))
            selected_parents(i, :) = population(idx(1), :);
        else
            selected_parents(i, :) = population(idx(2), :);
        end
    end
end