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Submission #340082

# Submission time Handle Problem Language Result Execution time Memory
340082 2020-12-26T20:39:51 Z wildturtle One-Way Streets (CEOI17_oneway) C++17
100 / 100
 487 ms 43376 KB 
#include<bits/stdc++.h>
using namespace std;
long long a,b,c,d,i,e,f,g,n,m,k,l,t,q;
long long disc[500005],low[500005],A[500005],B[500005],C[500005],D[500005],E[500005];
long long P[22][500005],br[500005],ans[500005],in[500005],out[500005];
vector < pair <long long , long long > > v[500005];
void dfs(long long x,long long y) {
    t++;
    disc[x]=t; low[x]=t;
    for(long long i=0;i<v[x].size();i++) {
        if(v[x][i].first==x) continue;
        if(disc[v[x][i].first]==0) {
            P[0][v[x][i].first]=x; D[v[x][i].first]=D[x]+1; E[v[x][i].first]=v[x][i].second;
            dfs(v[x][i].first,x);
            low[x]=min(low[x],low[v[x][i].first]);
            if(low[v[x][i].first]>disc[x]) br[v[x][i].first]=1;
        }
        else {
            if(P[0][v[x][i].first]==x) br[v[x][i].first]=0;
            if(v[x][i].first!=P[0][x]) low[x]=min(low[x],disc[v[x][i].first]);
        }
    }
}
int LCA(int u, int v) {
    if(D[u]<D[v]) swap(u, v);
    for(int k = 18 - 1; ~k; k--)
        if (D[P[k][u]]>=D[v]) u=P[k][u];
    if(u==v) return u;
    for (int k=18-1; ~k; k--)
        if(P[k][u]!=P[k][v]) { u=P[k][u]; v=P[k][v]; }
    return P[0][u];
}
long long get_col(long long x) {
  if (C[x] == x)
    return x;
  C[x] = get_col(C[x]);
  return C[x];
}
int main() {
    cin>>n>>m;
    for(long long i=0;i<m;i++) {
        cin>>A[i]>>B[i];
        v[A[i]].push_back({B[i],i});
        v[B[i]].push_back({A[i],i});
    }
    for(long long i=1;i<=n;i++) {
        if(disc[i]==0) dfs(i,0);
    }
    ////
    /*
    for(long long i=1;i<=n;i++) {
        cout<<E[i]<<" ";
    }
    cout<<endl;
    */////
    for(long long i=1;i<18;i++) {
        for(long long j=1;j<=n;j++) {
            P[i][j]=P[i-1][P[i-1][j]];
        }
    }
    for(long long i=1;i<=n;i++) {
        C[i]=i;
    }
    cin>>q;
    for(long long i=1;i<=q;i++) {
        cin>>a>>b;
        l=LCA(a,b);
        //cout<<l<<" ";
        a=get_col(a); b=get_col(b);
        //cout<<b<<" ";
        while(D[a]>D[l]) {
            if(br[a]==1) ans[E[a]]=-1;
            C[a]=P[0][a];
            a=get_col(a);
        }
        while(D[b]>D[l]) {
            if(br[b]==1) ans[E[b]]=1;
            C[b]=P[0][b];
            b=get_col(b);
        }
    }
    //cout<<endl;
    for(long long i=1;i<=n;i++) {
        if(br[i]==1 && B[E[i]]!=i) ans[E[i]]*=-1;
    }
    for(long long i=0;i<m;i++) {
        if(ans[i]==0) cout<<"B";
        else if(ans[i]==1) cout<<"R";
        else cout<<"L";
    }
}

Compilation message

oneway.cpp: In function 'void dfs(long long int, long long int)':
oneway.cpp:10:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for(long long i=0;i<v[x].size();i++) {
      |                       ~^~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12268 KB Output is correct
2 Correct 8 ms 12268 KB Output is correct
3 Correct 9 ms 12524 KB Output is correct
4 Correct 9 ms 12524 KB Output is correct
5 Correct 9 ms 12652 KB Output is correct
6 Correct 9 ms 12396 KB Output is correct
7 Correct 9 ms 12524 KB Output is correct
8 Correct 10 ms 12524 KB Output is correct
9 Correct 9 ms 12396 KB Output is correct
10 Correct 9 ms 12396 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12268 KB Output is correct
2 Correct 8 ms 12268 KB Output is correct
3 Correct 9 ms 12524 KB Output is correct
4 Correct 9 ms 12524 KB Output is correct
5 Correct 9 ms 12652 KB Output is correct
6 Correct 9 ms 12396 KB Output is correct
7 Correct 9 ms 12524 KB Output is correct
8 Correct 10 ms 12524 KB Output is correct
9 Correct 9 ms 12396 KB Output is correct
10 Correct 9 ms 12396 KB Output is correct
11 Correct 95 ms 23532 KB Output is correct
12 Correct 104 ms 26988 KB Output is correct
13 Correct 127 ms 31692 KB Output is correct
14 Correct 146 ms 37356 KB Output is correct
15 Correct 140 ms 39148 KB Output is correct
16 Correct 131 ms 38636 KB Output is correct
17 Correct 131 ms 40300 KB Output is correct
18 Correct 131 ms 38636 KB Output is correct
19 Correct 124 ms 41452 KB Output is correct
20 Correct 102 ms 29036 KB Output is correct
21 Correct 101 ms 29856 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 12268 KB Output is correct
2 Correct 8 ms 12268 KB Output is correct
3 Correct 9 ms 12524 KB Output is correct
4 Correct 9 ms 12524 KB Output is correct
5 Correct 9 ms 12652 KB Output is correct
6 Correct 9 ms 12396 KB Output is correct
7 Correct 9 ms 12524 KB Output is correct
8 Correct 10 ms 12524 KB Output is correct
9 Correct 9 ms 12396 KB Output is correct
10 Correct 9 ms 12396 KB Output is correct
11 Correct 95 ms 23532 KB Output is correct
12 Correct 104 ms 26988 KB Output is correct
13 Correct 127 ms 31692 KB Output is correct
14 Correct 146 ms 37356 KB Output is correct
15 Correct 140 ms 39148 KB Output is correct
16 Correct 131 ms 38636 KB Output is correct
17 Correct 131 ms 40300 KB Output is correct
18 Correct 131 ms 38636 KB Output is correct
19 Correct 124 ms 41452 KB Output is correct
20 Correct 102 ms 29036 KB Output is correct
21 Correct 101 ms 29856 KB Output is correct
22 Correct 487 ms 40300 KB Output is correct
23 Correct 430 ms 38648 KB Output is correct
24 Correct 433 ms 38636 KB Output is correct
25 Correct 444 ms 43376 KB Output is correct
26 Correct 441 ms 39916 KB Output is correct
27 Correct 393 ms 38764 KB Output is correct
28 Correct 103 ms 18028 KB Output is correct
29 Correct 344 ms 28780 KB Output is correct
30 Correct 320 ms 29292 KB Output is correct
31 Correct 347 ms 29036 KB Output is correct
32 Correct 379 ms 34412 KB Output is correct