在C++中获取数字的所有组合

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

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

    // 获取数字的所有组合
    std::vector<int> combinations;
    std::size_t index = 0;
    do {
        combinations.push_back(nums[index]);
        index = std::next_permutation(nums.begin(), nums.end(), index);
    } while (index != nums.size());

    // 输出数字的所有组合
    for (const int& combination : combinations) {
        std::cout << combination << ' ';
    }
    std::cout << std::endl;

    return 0;
}

1 2 3
1 3 2
2 1 3
2 3 1
3 1 2
3 2 1

#include <iostream>
#include <algorithm>

int main() {
    int n = 5;

    // 获取数字的所有组合
    std::vector<int> nums(n);
    std::iota(nums.begin(), nums.end(), 0);
    std::sort(nums.begin(), nums.end());
    do {
        for (int i = 0; i < n; ++i) {
            std::cout << nums[i] << ' ';
        }
        std::cout << std::endl;
    } while (std::next_permutation(nums.begin(), nums.end()));

    return 0;
}