题解 | GCPC总决赛

#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    vector<int> a(n);
    vector<int> b(n);
    for (int i = 0; i < n; i++)
        cin >> a[i];
    for (int i = 0; i < n; i++)
        cin >> b[i];

    vector<int> p(n, 0);
    iota(p.begin(), p.end(), 0);

    ll win = 0LL;
    ll lose = 0LL;
    ll draw = 0LL;
    do {
        int dark = 0;
        int yxl = 0;
        for (int i = 0; i < n; i++) {
            if (a[i] > b[p[i]])
                dark++;
            else if (a[i] < b[p[i]])
                yxl++;
        }
        if (dark > yxl)
            win++;
        else if (dark < yxl)
            lose++;
        else
            draw++;
    } while (next_permutation(p.begin(), p.end()));

    cout << win << " " << lose << " " << draw << endl;
}

暴力枚举。