Submission #636246

#	Time	Username	Problem	Language	Result	Execution time	Memory
636246		amirhoseinfar1385	Subtree (INOI20_subtree)	C++17	100 / 100	89 ms	25192 KiB

Main

#include<bits/stdc++.h>
using namespace std;
long long n,m;
vector<vector<long long>>adj;
vector<long long>par;
vector<long long>vaz;
vector<long long>res,resa[2][2],we;
vector<bool>vis;
long long mod=1e9+7;
void solvef(long long u){
	if(we[u]!=0){
		vaz[u]=1;
	}
	vis[u]=1;
	vector<long long>adja;
	for(int i=0;i<adj[u].size();i++){
		if(vis[adj[u][i]]==0){
			adja.push_back(adj[u][i]);
		}
	}
	adj[u]=adja;
	long long counta=0;
	adja.clear();
	for(int i=0;i<adj[u].size();i++){
		counta++;
		we[adj[u][i]]++;
	}
	for(int i=0;i<adj[u].size();i++){
		if(vis[adj[u][i]]==0){
			we[adj[u][i]]--;
			counta--;
			solvef(adj[u][i]);
			we[u]+=we[adj[u][i]];
			adja.push_back(adj[u][i]);
			if(we[adj[u][i]]>0){
				swap(adja[0],adja[adja.size()-1]);
			}
		}
	}
	if(counta!=0){
		vaz[u]=2;
	}
	we[u]-=counta;
	adj[u]=adja;
}

void solves(long long u){
	vis[u]=1;
	for(int i=0;i<adj[u].size();i++){
		solves(adj[u][i]);
	}
	if(vaz[u]==1){
		for(int i=0;i<adj[u].size();i++){
			res[u]*=res[adj[u][i]]+1;
			res[u]%=mod;
		}
		resa[1][0][u]=res[u];
		resa[0][1][u]=1;
		return ;
	}
	if(vaz[u]==0){
		for(int i=0;i<adj[u].size();i++){
			res[u]*=res[adj[u][i]]+1;
			res[u]%=mod;
		}
		for(int i=0;i<adj[u].size();i++){
			if(i==0){
				resa[1][0][u]+=resa[1][0][adj[u][i]];
				resa[1][1][u]+=resa[1][1][adj[u][i]]+resa[0][1][adj[u][i]];
				resa[0][1][u]+=resa[1][0][adj[u][i]]+resa[0][1][adj[u][i]];
				resa[1][0][u]%=mod;
				resa[1][1][u]%=mod;
				resa[0][1][u]%=mod;
				continue;
			}
			resa[1][1][u]*=res[adj[u][i]]+1;
			resa[1][1][u]%=mod;
			resa[1][0][u]*=res[adj[u][i]]+1;
			resa[1][0][u]%=mod;
		}
		return ;
	}
	if(vaz[u]==2){
		res[u]--;
		for(int i=0;i<adj[u].size();i++){
			if(i==0){
				res[u]+=resa[1][1][adj[u][i]]+resa[0][1][adj[u][i]];
				res[u]%=mod;
				continue;
			}
			res[u]*=res[adj[u][i]]+1;
			res[u]%=mod;
		}
		return ;
	}
}

int main(){
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m;
	adj.resize(n+1);
	par.resize(n+1);
	vis.resize(n+1);
	vaz.resize(n+1);
	res.resize(n+1,1);
	for(int i=0;i<2;i++){
		for(int j=0;j<2;j++){
			resa[i][j].resize(n+1);
		}
	}
	we.resize(n+1);
	for(int i=0;i<m;i++){
		long long u,v;
		cin>>u>>v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	solvef(1);
	vis.clear();
	vis.resize(n+1);
	solves(1);
	long long mainres=0;
	for(int i=1;i<=n;i++){
	//	cout<<i<<" "<<res[i]<<" "<<resa[1][0][i]<<" "<<resa[1][1][i]<<" "<<resa[0][1][i]<<" "<<vaz[i]<<endl;
		mainres+=res[i];
		mainres%=mod;
	}
	cout<<mainres<<endl;
}

Compilation message (stderr)

Main.cpp: In function 'void solvef(long long int)':
Main.cpp:16:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |  for(int i=0;i<adj[u].size();i++){
      |              ~^~~~~~~~~~~~~~
Main.cpp:24:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   24 |  for(int i=0;i<adj[u].size();i++){
      |              ~^~~~~~~~~~~~~~
Main.cpp:28:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  for(int i=0;i<adj[u].size();i++){
      |              ~^~~~~~~~~~~~~~
Main.cpp: In function 'void solves(long long int)':
Main.cpp:49:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |  for(int i=0;i<adj[u].size();i++){
      |              ~^~~~~~~~~~~~~~
Main.cpp:53:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |   for(int i=0;i<adj[u].size();i++){
      |               ~^~~~~~~~~~~~~~
Main.cpp:62:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |   for(int i=0;i<adj[u].size();i++){
      |               ~^~~~~~~~~~~~~~
Main.cpp:66:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   66 |   for(int i=0;i<adj[u].size();i++){
      |               ~^~~~~~~~~~~~~~
Main.cpp:85:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |   for(int i=0;i<adj[u].size();i++){
      |               ~^~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 12 / 12
• Subtask 3: 30 / 30
• Subtask 4: 50 / 50