Submission #864549

#	Time	Username	Problem	Language	Result	Execution time	Memory
864549		maks007	Railway (BOI17_railway)	C++14	8 / 100	1054 ms	27552 KiB

railway

// Bismi ALlah
#include "bits/stdc++.h"

using namespace std;

vector <vector <int>> g;
int f;
multiset <pair <int,int>> path;

void dfs(int v, const int & target, int p = -1) {
	if(p != -1) path.insert({min(v, p), max(v, p)});
	if(v == target) {
		f = 1;
		return;
	}
	for(auto u : g[v]) {
		if(u == p) continue;
		dfs(u, target, v);
		if(f) return;
	}
	path.erase(path.find({min(v, p), max(v, p)}));
}

signed main () {
	int n, m, k;
	cin >> n >> m >> k;
	g.resize(n);
	map <pair <int,int>,int> edge;
	vector <int> cnt(n-1, 0);
	for(int i = 0; i < n - 1; i ++) {
		int u, v;
		cin >> u >> v;
		u --, v --;
		edge[{min(u, v), max(u, v)}] = i;
		g[v].push_back(u);
		g[u].push_back(v);
	}	
	for(;m>=1;m--) {
		int sz;
		cin >> sz;
		vector <int> need;
		for(int v;sz>=1;sz--) {
			cin >> v;
			v --;
			need.push_back(v);
		}
		int prev = need[0];
		for(int i = 1; i < need.size(); i ++) {
			f = 0;
			dfs(need[i], prev);
		}
		set <pair <int,int>> forPath;
		for(auto i : path) forPath.insert(i);
		for(auto i : forPath) {
		//	cout << i.first + 1 << " " << i.second + 1 << "\n";	
			cnt[edge[i]] ++;
		}
		//cout << "\n";
		path.clear();
	}
	vector <int> ans;
	for(int i= 0; i < cnt.size(); i ++) {
		if(cnt[i] >= k) ans.push_back(i + 1);
	}
	cout << ans.size() << "\n";
	for(auto i : ans) cout << i << " ";
	return 0;
}

Compilation message (stderr)

railway.cpp: In function 'int main()':
railway.cpp:48:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |   for(int i = 1; i < need.size(); i ++) {
      |                  ~~^~~~~~~~~~~~~
railway.cpp:62:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |  for(int i= 0; i < cnt.size(); i ++) {
      |                ~~^~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25