Submission #696628

#	Time	Username	Problem	Language	Result	Execution time	Memory
696628		SanguineChameleon	Šarenlist (COCI22_sarenlist)	C++17	110 / 110	39 ms	328 KiB

Main

// BEGIN BOILERPLATE CODE

#include <bits/stdc++.h>
using namespace std;

#ifdef KAMIRULEZ
	const bool kami_loc = true;
	const long long kami_seed = 69420;
#else
	const bool kami_loc = false;
	const long long kami_seed = chrono::steady_clock::now().time_since_epoch().count();
#endif

const string kami_fi = "kamirulez.inp";
const string kami_fo = "kamirulez.out";
mt19937_64 kami_gen(kami_seed);

long long rand_range(long long rmin, long long rmax) {
	uniform_int_distribution<long long> rdist(rmin, rmax);
	return rdist(kami_gen);
}

long double rand_real(long double rmin, long double rmax) {
	uniform_real_distribution<long double> rdist(rmin, rmax);
	return rdist(kami_gen);
}

void file_io(string fi, string fo) {
	if (fi != "" && (!kami_loc || fi == kami_fi)) {
		freopen(fi.c_str(), "r", stdin);
	}
	if (fo != "" && (!kami_loc || fo == kami_fo)) {
		freopen(fo.c_str(), "w", stdout);
	}
}

void set_up() {
	if (kami_loc) {
		file_io(kami_fi, kami_fo);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

void just_do_it();

void just_exec_it() {
	if (kami_loc) {
		auto pstart = chrono::steady_clock::now();
		just_do_it();
		auto pend = chrono::steady_clock::now();
		long long ptime = chrono::duration_cast<chrono::milliseconds>(pend - pstart).count();
		string bar(50, '=');
		cout << '\n' << bar << '\n';
		cout << "Time: " << ptime << " ms" << '\n';
	}
	else {
		just_do_it();
	}
}

int main() {
	set_up();
	just_exec_it();
	return 0;
}

// END BOILERPLATE CODE

// BEGIN MAIN CODE

const long long mod = 1e9 + 7;
vector<pair<int, int>> adj[70];
vector<int> g[70];
bool f[70];
vector<int> cur;
vector<vector<int>> paths;
long long pw[70];
int fin;

void dfs1(int u, int pr) {
	if (u == fin) {
		paths.push_back(cur);
	}
	for (auto x: adj[u]) {
		int v = x.first;
		int id = x.second;
		if (v != pr) {
			cur.push_back(id);
			dfs1(v, u);
			cur.pop_back();
		}
	}
}

void dfs2(int u) {
	f[u] = true;
	for (auto v: g[u]) {
		if (!f[v]) {
			dfs2(v);
		}
	}
}

void just_do_it() {
	int n, m, k;
	cin >> n >> m >> k;
	pw[0] = 1;
	for (int i = 1; i <= n; i++) {
		pw[i] = pw[i - 1] * k % mod;
	}
	for (int i = 1; i <= n - 1; i++) {
		int u, v;
		cin >> u >> v;
		adj[u].push_back({v, i});
		adj[v].push_back({u, i});
	}
	for (int i = 0; i < m; i++) {
		int u, v;
		cin >> u >> v;
		fin = v;
		dfs1(u, -1);
	}
	long long res = 0;
	for (int i = 0; i < (1 << m); i++) {
		for (int j = 1; j <= n - 1; j++) {
			g[j].clear();
			f[j] = false;
		}
		int B = 0;
		for (int j = 0; j < m; j++) {
			if ((i >> j) & 1) {
				B++;
				int sz = paths[j].size();
				for (int k = 0; k < sz - 1; k++) {
					int u = paths[j][k];
					int v = paths[j][k + 1];
					g[u].push_back(v);
					g[v].push_back(u);
				}
			}
		}
		int cnt = 0;
		for (int j = 1; j <= n - 1; j++) {
			if (!f[j]) {
				cnt++;
				dfs2(j);
			}
		}
		if (B & 1) {
			res = (res + mod - pw[cnt]) % mod;
		}
		else {
			res = (res + pw[cnt]) % mod;
		}
	}
	cout << res;
}

// END MAIN CODE

Compilation message (stderr)

Main.cpp: In function 'void file_io(std::string, std::string)':
Main.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 65 / 65