rk又是卡python的一次。菜是原罪----不会用c++
那就学习一下next_permutation
python 14/25
c++ 25/25

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

void split_numbers(int n, std::vector<int>& digits) {
    std::sort(digits.begin(), digits.end());
    std::vector<int> sum_to_perms;

    do {
        int temp = 0;
        for (int i = 0; i < n; ++i) {
            temp = temp * 10 + digits[i];
        }
        sum_to_perms.push_back(temp);
    } while (std::next_permutation(digits.begin(), digits.end()));

    int m = sum_to_perms.size();
    long long ss = 0;
    for (auto& num : sum_to_perms) {
        ss += num * num;
    }
    long long target = ss / 2;

    for (int i = 0; i < (1 << m); ++i) {
        long long sum_squares = 0;
        int count = 0;
        std::vector<int> ans;
        for (int j = 0; j < m; ++j) {
            if (i & (1 << j)) {
                ans.push_back(sum_to_perms[j]);
                sum_squares += static_cast<long long>(sum_to_perms[j]) * sum_to_perms[j];
                ++count;
            }
        }
        if (sum_squares == target && count == m / 2) {
            for (int num : ans) {
                std::cout << num << std::endl;
            }
            return;
        }
    }
}

int main() {
    int n;
    std::cin >> n;
    std::vector<int> digits(n);
    for (int i = 0; i < n; ++i) {
        std::cin >> digits[i];
    }

    split_numbers(n, digits);

    return 0;
}

import itertools

def split_numbers(n, nums):
    permutations = itertools.permutations(nums)
    nums = []
    for perm in permutations:
        tep = 0
        for c in perm:
            tep = tep * 10 + c
        nums.append(tep)
    m = len(nums)
    ss = 0
    for c in nums:
        ss += c * c
    target = ss / 2
    for i in range (1 << m):
        a = 0
        ans = []
        b = 0
        for j in range(m):
            if i >> j & 1:
                a += 1
                ans.append(nums[j])
                b += nums[j] ** 2
                if b == target and a == m / 2:
                    for c in ans:
                        print(c)
                    return
                if a > m / 2 or a > target:
                    break



n = int(input())
nums = list(map(int, input().split()))
split_numbers(n, nums)