제출 #655822

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
655822		manizare	One-Way Streets (CEOI17_oneway)	C++14	0 / 100	13 ms	27732 KiB

oneway

#include<bits/stdc++.h>
#define all(a) a.begin(),a.end()
#define pb push_back

using namespace std ;

const int maxn = 5e5 + 10 , maxq = 502 , inf = 1e9 , mod = 1e9+7 ;
vector <pair <int , int > > G[maxn] ;
vector <int>  l[maxn] ;
int dp[maxn] , mark2[maxn] , mark[maxn] , par[maxn]  , cnt = 1 ,c[maxn] , st[maxn] , en[maxn] , pr[maxn] , pp[maxn] , ans[maxn]; 
pair <int , int > ed[maxn] ;
void dfs(int v){ 
	mark[v] = 1;
	for(int i = 0; i < G[v].size() ; i++){
		int u = G[v][i].first , id = G[v][i].second ;
		if(mark[u] == 1){
			if(mark2[id] == 0){
				dp[v] ++ ;
				dp[u] -- ;
				ans[id] = 3 ;
				mark2[id] = 1; 
			}
			continue ;
		}
		mark2[id] = 1;
		par[u] = id ;
		dfs(u) ;
		dp[v]+=dp[u];
	}
}

void dfs2(int v , int r){
	mark[v] = 1;
	c[v] = r ;
	for(int i = 0; i < G[v].size() ; i++){
		int u = G[v][i].first , id = G[v][i].second ;
		if(mark[u] == 1)continue ;
		if(dp[u] == 0){
			cnt ++;
			//cout << v << " " << u << "<---\n";
			if(ed[id].first == u){
				ans[id] = 1;//l 
			}else{
				ans[id] = 2; //r
			}
			pr[cnt] = id ;
			pp[cnt] = r ;
			l[r].pb(cnt);
			dfs2(u , cnt);
		}else{
			dfs2(u , r);
		}
	}
}
int sec = 1 ;
void dfs3(int v){
	mark[v] = 1;
	st[v] = sec ;
	sec++;
	for(int i = 0 ;i < l[v].size() ; i++){
		int u = l[v][i] ;
		dfs3(u);
	}
	en[v] = sec;
	sec++;
}

signed main(){
	ios::sync_with_stdio(false); cin.tie(0);cout.tie(0);
	int n , m ;
	cin >> n >> m ;
	for(int i =1  ;i <= m ; i++){
		int v , u ;
		cin >> v >> u ;
		if(v==u){
			ans[i] = 3; 
			continue ;
		}
		G[v].pb({u,i});
		G[u].pb({v,i});
		ed[i] = {v , u} ;
	}
	for(int i = 1; i <= n ; i++){
		if(mark[i] == 1)continue ;
		dfs(i);
	}
	for(int i =1 ; i <= n ; i++){
		if(par[i] == 0)continue ;
		if(dp[i] >= 1){
			ans[par[i]] = 3 ;
		}
	}
	memset(mark , 0 , sizeof mark);
	memset(mark2 , 0 , sizeof mark2);
	vector <int> vec ;
	for(int i =1; i <= n ; i ++){
		if(mark[i] == 1)continue ;
		vec.pb(cnt);
		dfs2(i ,cnt ) ;
		cnt++;
	}
	memset(mark , 0 , sizeof mark);
	for(int i =0 ; i < vec.size() ;i++){
		int u = vec[i]; 
		dfs3(u);
	}
	int q ;
	cin >> q ;
	while(q--){
		int v , u ;
		cin >> v >> u ;
		if(c[v] == c[u])continue ;
		v = c[v] ;
		u = c[u] ;
		while(!(st[v] <= st[u]  && en[v] >= en[u])){
			ans[pr[v]] = (3 - ans[pr[v]]) ;
			v = pp[v] ; 
		}
	}
	for(int i = 1 ; i <= m ; i++){
		if(ans[i] == 3){
			cout << "B";
		}
		if(ans[i] == 2){
			cout << "R";
		}
		if(ans[i] == 1){
			cout << "L" ;
		}
	}
}

컴파일 시 표준 에러 (stderr) 메시지

oneway.cpp: In function 'void dfs(int)':
oneway.cpp:14:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |  for(int i = 0; i < G[v].size() ; i++){
      |                 ~~^~~~~~~~~~~~~
oneway.cpp: In function 'void dfs2(int, int)':
oneway.cpp:35:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   35 |  for(int i = 0; i < G[v].size() ; i++){
      |                 ~~^~~~~~~~~~~~~
oneway.cpp: In function 'void dfs3(int)':
oneway.cpp:60:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   60 |  for(int i = 0 ;i < l[v].size() ; i++){
      |                 ~~^~~~~~~~~~~~~
oneway.cpp: In function 'int main()':
oneway.cpp:103:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  103 |  for(int i =0 ; i < vec.size() ;i++){
      |                 ~~^~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40