Divide set into two subset with minimum sum difference

gistfile1.txt

#include <bits/stdc++.h>

using namespace std;

typedef unsigned long long ull;


int main(void) {
    ios::sync_with_stdio(false);
    int n;
    cin >> n;

    vector<long long> m(n);
    for(int i = 0; i < n; i++) {
        cin >> m[i];
    }

    pair< vector<long long>, int>  ans;
    sort(m.begin(), m.end());
    long long prev_sub = LONG_LONG_MAX;
    long long totalSum = accumulate(m.begin(), m.end(), 0);

    while(true) {
        for(int i = 1; i < m.size(); i++) {
            long long partialSum = accumulate(m.begin(), m.begin() + i, 0);
            if(abs(totalSum - partialSum - partialSum) < prev_sub) {
                prev_sub = abs(totalSum - partialSum - partialSum);
                ans = make_pair(m, i);
            }
        }

        if(!next_permutation(m.begin(), m.end()))
            break;
    }

    cout << "A = ";
    for(int i = 0; i < ans.second; i++)
        cout << ans.first[i] << " ";
    cout << endl;

    cout << "B = ";
    for(int i = ans.second; i < ans.first.size(); i++)
        cout << ans.first[i] << " ";
    cout << endl;

     return 0;
}