kek.cpp

#include <iostream>
#include <functional>
#include <algorithm>
#include <vector>
#include <set>
#include <string>
#include <list>
#include <map>
using namespace std;

#define mp make_pair


double res = 0;


int find(int x, vector<int> v) {
    int count = 0;
    for (int i = 0; i < v.size(); ++i) {
        count += v[i] == x;
    }
    return count;
}
set<vector<int>> s;
void rec(vector<int> a,vector<int> v, double sum, double p,int d) {
    if (d == 3) {
        auto it = s.find(a);
        if (it != s.end()) return;
        s.insert(a);
        for (int i = 0; i < a.size(); ++i) {
            cout << a[i] << " ";
        }
        cout << p;
        cout << "\n\n";
        res += (sum*p);
        return;
    }
    for (int i = 0; i < v.size(); ++i) {
        int x = v[i];
        v.erase(v.begin() + i);
        a.push_back(x);
        rec(a,v,sum+x,p*((double)find(x, v) + 1) / (v.size() + 1),d+1);
        a.pop_back();
        v.insert(v.begin() + i,x);
    }
}

int main() {
#ifdef _KOCH
    freopen("read.txt", "r", stdin);
#else
    // freopen("multimap.in", "r", stdin);
    // freopen("multimap.out", "w", stdout);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int  n;
    cin >> n;
    vector<int> v(n);
    for (int i = 0; i < n; ++i) {
        cin >> v[i];
    }
    int sum = 0;
    vector<int> a;
    rec(a,v, 0, 1,0);
    return 0;
}