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;
}