Submission #510231

#	Time	Username	Problem	Language	Result	Execution time	Memory
510231		MOUF_MAHMALAT	One-Way Streets (CEOI17_oneway)	C++14	0 / 100	1 ms	328 KiB

oneway

#include<bits/stdc++.h>
#define all(s) s.begin(),s.end()
#define F first
#define S second
using namespace std;
typedef int ll;
ll n,m,q,h[100009],low[100009],x,y,t,c[2][100009];
vector<vector<ll> >v;
bool b[100009];
pair<ll,ll>p[100009];
map<pair<ll,ll>,char>mp;
void go(ll d,ll p)
{
    b[d]=1;
    for(auto z:v[d])
        if(!b[z])
        {
            go(z,d);
            c[0][d]+=c[0][z];
            c[1][d]+=c[1][z];
        }
}
void dfs(ll d,ll p)
{
    h[d]=low[d]=t++;
    b[d]=1;
    for(auto z:v[d])
    {
        if(!b[z])
        {
            dfs(z,d);
            low[d]=min(low[d],low[z]);
            if(low[z]>h[d])
            {
                if(c[0][d]>c[0][z]&&c[1][z])
                    mp[ {d,z}]='R',mp[ {z,d}]='L';
                else if(c[1][d]>c[1][z]&&c[0][z])
                    mp[ {d,z}]='L',mp[ {z,d}]='R';
                else
                    mp[ {d,z}]=mp[ {d,z}]='B';
            }
        }
        else if(z!=p)
        {
            low[d]=min(low[d],h[z]);
            mp[ {z,d}]=mp[ {d,z}]='B';
        }
        else mp[{z,d}]=mp[{d,z}]='B';
    }
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
    cin>>n>>m;
    v.resize(n+1);
    for(ll i=1; i<=m; i++)
    {
        cin>>x>>y;
        p[i]= {x,y};
        v[x].push_back(y);
        v[y].push_back(x);
    }
    cin>>q;
    while(q--)
    {
        cin>>x>>y;
        c[0][x]=1;
        c[1][y]=1;
    }
    go(1,1);
    memset(b,0,sizeof b);
    dfs(1,1);
    for(ll i=1; i<=m; i++)
    {
        if(p[i].F==p[i].S)
            cout<<"B";
        else
            cout<<mp[p[i]];
    }
    return 0;
}

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