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Submission #701135

# Submission time Handle Problem Language Result Execution time Memory
701135 2023-02-20T07:39:43 Z Darren0724 One-Way Streets (CEOI17_oneway) C++14
100 / 100
 96 ms 15864 KB 
#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()
int n,m;
vector<int> a,b;
vector<int> low,in;
vector<vector<int>> adj;
vector<int> ab,br;
vector<int> num;
vector<int> bcc;
vector<int> st;
vector<int> dx;
vector<int> dis;
int timet=1,bcc_cnt=0;
void dfs1(int k,int pa){
    in[k]=low[k]=timet++;
    st.push_back(k);
    int tmp=0;
    for(int i:adj[k]){
        int j=ab[i]^k;
        if(pa==j){
            tmp++;
            if(tmp==1){
                continue;
            }
        }
        if(low[j]){
            low[k]=min(low[k],in[j]);
        }
        else{
            dfs1(j,k);
            low[k]=min(low[k],low[j]);
            if(low[j]>in[k]){
                br[i]=1;
            }
        }
    }
    if(low[k]==in[k]){
        while(st.back()!=k){
            bcc[st.back()]=bcc_cnt;
            st.pop_back();
        }
        st.pop_back();
        bcc[k]=bcc_cnt;
        bcc_cnt++;
    }
}
void dfs2(int k,int pa){
    for(int j:adj[k]){
        if(j==pa){
            continue;
        }
        dis[j]=dis[k]+1;
        dfs2(j,k);
        dx[k]+=dx[j];
    }
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin>>n>>m;
    adj.resize(n);
    in.resize(n);
    low.resize(n);
    ab.resize(m);
    br.resize(m);
    a.resize(m);
    b.resize(m);
    bcc.resize(n);
    for(int i=0;i<m;i++){
        cin>>a[i]>>b[i];a[i]--;b[i]--;
        adj[a[i]].push_back(i);
        adj[b[i]].push_back(i);
        ab[i]=a[i]^b[i];
    }
    for(int i=0;i<n;i++){
        if(in[i]==0)dfs1(i,-1);
    }
    for(int i=0;i<m;i++){
        a[i]=bcc[a[i]];
        b[i]=bcc[b[i]];
    }
    adj.clear();
    adj.resize(bcc_cnt+1);
    dis.resize(bcc_cnt+1);
    dx.resize(bcc_cnt+1);
    for(int i=0;i<m;i++){
        if(br[i]==0){
            continue;
        }
        adj[a[i]].push_back(b[i]);
        adj[b[i]].push_back(a[i]);
    }
    for(int i=0;i<bcc_cnt;i++){
        sort(all(adj[i]));
        adj[i].resize(unique(all(adj[i]))-adj[i].begin());
    }
    int q;cin>>q;
    for(int i=0;i<q;i++){
        int c,d;cin>>c>>d;c--;d--;
        c=bcc[c],d=bcc[d];
        dx[c]++;
        dx[d]--;
    }
    for(int i=0;i<bcc_cnt;i++){
        if(dis[i]==0){
            dis[i]=1;
            dfs2(i,-1);
        }
    }
    for(int i=0;i<m;i++){
        if(!br[i]){
            assert(abs(dis[a[i]]-dis[b[i]])==0);
            cout<<'B';
        }
        else{
            assert(abs(dis[a[i]]-dis[b[i]])==1);
            if(dis[a[i]]>dis[b[i]]){
                if(dx[a[i]]==0){
                    cout<<'B';
                }
                else if(dx[a[i]]>0){
                    cout<<'R';
                }
                else{
                    cout<<'L';
                }
            }
            else{
                if(dx[b[i]]==0){
                    cout<<'B';
                }
                else if(dx[b[i]]>0){
                    cout<<'L';
                }
                else{
                    cout<<'R';
                }
            }
        }
    }

    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 34 ms 5520 KB Output is correct
12 Correct 35 ms 6768 KB Output is correct
13 Correct 43 ms 8420 KB Output is correct
14 Correct 57 ms 9960 KB Output is correct
15 Correct 62 ms 10272 KB Output is correct
16 Correct 90 ms 10996 KB Output is correct
17 Correct 71 ms 12748 KB Output is correct
18 Correct 73 ms 10936 KB Output is correct
19 Correct 59 ms 13928 KB Output is correct
20 Correct 35 ms 7212 KB Output is correct
21 Correct 34 ms 6936 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 34 ms 5520 KB Output is correct
12 Correct 35 ms 6768 KB Output is correct
13 Correct 43 ms 8420 KB Output is correct
14 Correct 57 ms 9960 KB Output is correct
15 Correct 62 ms 10272 KB Output is correct
16 Correct 90 ms 10996 KB Output is correct
17 Correct 71 ms 12748 KB Output is correct
18 Correct 73 ms 10936 KB Output is correct
19 Correct 59 ms 13928 KB Output is correct
20 Correct 35 ms 7212 KB Output is correct
21 Correct 34 ms 6936 KB Output is correct
22 Correct 76 ms 12760 KB Output is correct
23 Correct 84 ms 10928 KB Output is correct
24 Correct 96 ms 10956 KB Output is correct
25 Correct 85 ms 15864 KB Output is correct
26 Correct 73 ms 12316 KB Output is correct
27 Correct 87 ms 11068 KB Output is correct
28 Correct 27 ms 3008 KB Output is correct
29 Correct 55 ms 6744 KB Output is correct
30 Correct 51 ms 6884 KB Output is correct
31 Correct 49 ms 7244 KB Output is correct
32 Correct 56 ms 9604 KB Output is correct