제출 #394154

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
394154		CSQ31	One-Way Streets (CEOI17_oneway)	C++14	100 / 100	162 ms	37816 KiB

oneway

#pragma GCC optimize("Ofast") 
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
#define lb lower_bound
#define ub upper_bound
#define owo ios_base::sync_with_stdio(0);cin.tie(0);
#define MOD (ll)(998244353)
#define INF (ll)(1e18)
#define debug(...) fprintf(stderr, __VA_ARGS__),fflush(stderr)
#define time__(d) for(long blockTime = 0; (blockTime == 0 ? (blockTime=clock()) != 0 : false);\
debug("%s time : %.4fs\n", d, (double)(clock() - blockTime) / CLOCKS_PER_SEC))
typedef long long int ll;
typedef long double ld;
typedef pair<ll,ll> PII;
typedef pair<int,int> pii;
typedef vector<vector<int>> vii;
typedef vector<vector<ll>> VII;
ll gcd(ll a,ll b){if(!b)return a;else return gcd(b,a%b);}
const int MAXN = 2e5;
vii adj(MAXN);
vector<set<int>>tadj(MAXN);
vector<int>id(MAXN);
vector<int>tin(MAXN),low(MAXN);
stack<int>stk;
int timer = 0,scc = 0;
void tarjan(int v,int p){
	tin[v] = low[v] = ++timer;
	stk.push(v);
	bool pp = 0;
	for(int x:adj[v]){
		if(x != p || pp){
			if(!tin[x]){
				tarjan(x,v);
				low[v] = min(low[v],low[x]);
			}else{
				low[v] = min(low[v],tin[x]);
			}
		}else pp = 1;
	}
	if(low[v] == tin[v]){
		while(stk.top() != v){
			id[stk.top()] = scc;
			stk.pop();
		}
		stk.pop();
		id[v] = scc;
		scc++;
	}
}
vector<int>dep(MAXN),val(MAXN);
void dfs(int v,int u){
	for(int x:tadj[v]){
		if(x != u){
			dep[x] = dep[v]+1;
			dfs(x,v);
			val[v]+=val[x];
		}
	}
}
int main()
{
	owo
	int n,m;
	cin>>n>>m;
	vector<pii>e;
	for(int i=0;i<m;i++){
		int v,u;
		cin>>v>>u;
		adj[v].pb(u);
		adj[u].pb(v);
		e.pb({v,u});
	}
	for(int i=1;i<=n;i++){
		if(!tin[i])tarjan(i,-1);
	}
	//for(int i=1;i<=n;i++)cout<<id[i]<<" ";
	//cout<<'\n';
	for(pii x:e){
		if(id[x.fi] == id[x.se])continue;
		tadj[id[x.fi]].insert(id[x.se]);
		tadj[id[x.se]].insert(id[x.fi]);
	}
	int p;cin>>p;
	while(p--){
		int a,b;
		cin>>a>>b;
		val[id[a]]--;
		val[id[b]]++;
	}
	for(int i=1;i<=n;i++){
		if(!dep[id[i]]){
			dep[id[i]] = 1;
			dfs(id[i],-1);
		}
	}
	for(pii x:e){
		int a = id[x.fi];
		int b = id[x.se];
		if(a == b){cout<<"B";continue;}
		if(dep[a] > dep[b]){
		     if(val[a] <0)cout<<"R";
		     else if(!val[a])cout<<"B";
		     else cout<<"L";
			
		}
		else{
			if(val[b] <0)cout<<"L";
		     else if(!val[b])cout<<"B";
		     else cout<<"R";
		}
	}
}

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