C++：在新的库中生成组合

#include <iostream>
#include <vector>
#include <algorithm>

void generateCombinations(const std::vector<int>& elements, int length) {
    std::vector<bool> combination(elements.size(), false);
    std::fill(combination.begin(), combination.begin() + length, true);

    do {
        for (int i = 0; i < elements.size(); ++i) {
            if (combination[i]) {
                std::cout << elements[i] << " ";
            }
        }
        std::cout << std::endl;
    } while (std::next_permutation(combination.begin(), combination.end()));
}

int main() {
    std::vector<int> elements = {1, 2, 3, 4};
    int length = 2;

    generateCombinations(elements, length);

    return 0;
}