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Submission #905676

# Submission time Handle Problem Language Result Execution time Memory
905676 2024-01-13T04:10:05 Z andremfq One-Way Streets (CEOI17_oneway) C++17
100 / 100
 200 ms 39480 KB 
//solucao legal
#include <bits/stdc++.h>
//#pragma GCC optimize("Ofast")
#define fori(a,b) for(int i=a;i<b;i++)
#define forj(a,b) for(int j=a;j<b;j++)
#define fork(a,b) for(int k=a;k<b;k++)
#define ford(i,a,b) for(int i=a;i>=b;i--)
#define seto(x,i) memset(x,i,sizeof x)
#define inf 0x3f3f3f3f
#define INF 0x3f3f3f3f3f3f3f3f
#define pf first
#define ps second
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;

const int N=100010;
int n,m,p,a,b,c,scc,dfn[N],low[N],id[N],inx,dist[N],val[N];
bool ins[N];
stack<int> st;
vector<int> gr[N];
unordered_set<int> cgr[N];
pii edge[N];

void tarjan(int v,int p)
{
    dfn[v]=low[v]=++inx;
    ins[v]=true; st.push(v);
    for(auto i:gr[v])
    {
        if(i==p)
        {
            p=-1;
            continue;
        }
        if(!dfn[i])
        {
            tarjan(i,v);
            low[v]=min(low[v],low[i]);
        }
        else if(ins[i])
            low[v]=min(low[v],dfn[i]);
    }
    if(dfn[v]==low[v])
    {
        while(st.top()!=v)
        {
            id[st.top()]=scc;
            ins[st.top()]=0;
            st.pop();
        }
        id[st.top()]=scc;
        ins[st.top()]=0;
        st.pop();
        scc++;
    }
}
void dfs(int v,int p)
{
    for(auto i:cgr[v])
        if(i!=p)
        {
            dist[i]=dist[v]+1;
            dfs(i,v);
            val[v]+=val[i];
        }
}

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n>>m;
    fori(0,m)
    {
        cin>>edge[i].pf>>edge[i].ps;
        gr[edge[i].pf].push_back(edge[i].ps);
        gr[edge[i].ps].push_back(edge[i].pf);
    }
    fori(0,n)
        if(!dfn[i])
            tarjan(i,-1);
    fori(0,m)
        if(id[edge[i].pf]!=id[edge[i].ps])
        {
            cgr[id[edge[i].pf]].insert(id[edge[i].ps]);
            cgr[id[edge[i].ps]].insert(id[edge[i].pf]);
        }
    cin>>p;
    fori(0,p)
    {
        cin>>a>>b;
        val[id[a]]++;
        val[id[b]]--;
    }
    fori(0,scc)
        if(!dist[i])
            dfs(i,-1);
    fori(0,m)
    {
        a=id[edge[i].pf]; b=id[edge[i].ps];
        if(a==b)
            cout<<"B";
        if(dist[a]>dist[b])
        {
            if(val[a]>0)
                cout<<"R";
            if(val[a]==0)
                cout<<"B";
            if(val[a]<0)
                cout<<"L";
        }
        if(dist[a]<dist[b])
        {
            if(val[b]>0)
                cout<<"L";
            if(val[b]==0)
                cout<<"B";
            if(val[b]<0)
                cout<<"R";
        }
    }
    return 0;
}

/*idea
use tarjan to compress strongly connected components
all edges in scc are bidirectional
the new graph is a tree
for each path l-r set all of them in that direction
use tree difference array

*/

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 10584 KB Output is correct
2 Correct 3 ms 10584 KB Output is correct
3 Correct 3 ms 10588 KB Output is correct
4 Correct 5 ms 10840 KB Output is correct
5 Correct 5 ms 10844 KB Output is correct
6 Correct 3 ms 10584 KB Output is correct
7 Correct 4 ms 10840 KB Output is correct
8 Correct 4 ms 10844 KB Output is correct
9 Correct 4 ms 10588 KB Output is correct
10 Correct 5 ms 10588 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 10584 KB Output is correct
2 Correct 3 ms 10584 KB Output is correct
3 Correct 3 ms 10588 KB Output is correct
4 Correct 5 ms 10840 KB Output is correct
5 Correct 5 ms 10844 KB Output is correct
6 Correct 3 ms 10584 KB Output is correct
7 Correct 4 ms 10840 KB Output is correct
8 Correct 4 ms 10844 KB Output is correct
9 Correct 4 ms 10588 KB Output is correct
10 Correct 5 ms 10588 KB Output is correct
11 Correct 32 ms 14056 KB Output is correct
12 Correct 38 ms 14932 KB Output is correct
13 Correct 45 ms 16524 KB Output is correct
14 Correct 91 ms 21292 KB Output is correct
15 Correct 99 ms 22560 KB Output is correct
16 Correct 188 ms 32800 KB Output is correct
17 Correct 140 ms 34624 KB Output is correct
18 Correct 184 ms 32736 KB Output is correct
19 Correct 132 ms 35940 KB Output is correct
20 Correct 36 ms 15700 KB Output is correct
21 Correct 46 ms 15444 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 10584 KB Output is correct
2 Correct 3 ms 10584 KB Output is correct
3 Correct 3 ms 10588 KB Output is correct
4 Correct 5 ms 10840 KB Output is correct
5 Correct 5 ms 10844 KB Output is correct
6 Correct 3 ms 10584 KB Output is correct
7 Correct 4 ms 10840 KB Output is correct
8 Correct 4 ms 10844 KB Output is correct
9 Correct 4 ms 10588 KB Output is correct
10 Correct 5 ms 10588 KB Output is correct
11 Correct 32 ms 14056 KB Output is correct
12 Correct 38 ms 14932 KB Output is correct
13 Correct 45 ms 16524 KB Output is correct
14 Correct 91 ms 21292 KB Output is correct
15 Correct 99 ms 22560 KB Output is correct
16 Correct 188 ms 32800 KB Output is correct
17 Correct 140 ms 34624 KB Output is correct
18 Correct 184 ms 32736 KB Output is correct
19 Correct 132 ms 35940 KB Output is correct
20 Correct 36 ms 15700 KB Output is correct
21 Correct 46 ms 15444 KB Output is correct
22 Correct 163 ms 35924 KB Output is correct
23 Correct 158 ms 34008 KB Output is correct
24 Correct 200 ms 33876 KB Output is correct
25 Correct 130 ms 39480 KB Output is correct
26 Correct 133 ms 35420 KB Output is correct
27 Correct 143 ms 34024 KB Output is correct
28 Correct 28 ms 13040 KB Output is correct
29 Correct 61 ms 16320 KB Output is correct
30 Correct 64 ms 16452 KB Output is correct
31 Correct 56 ms 16936 KB Output is correct
32 Correct 74 ms 24240 KB Output is correct