#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++;
in[x]=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(v[x][i].first!=P[0][x]) low[x]=min(low[x],disc[v[x][i].first]);
}
out[x]=t;
}
int LCA(int u, int v) {
if(D[u]<D[v]) swap(u, v);
for(int k = 20 - 1; ~k; k--)
if (D[P[k][u]]>=D[v]) u=P[k][u];
if(u==v) return u;
for (int k=20-1; ~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<=20;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:11:24: 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]
11 | for(long long i=0;i<v[x].size();i++) {
| ~^~~~~~~~~~~~
# |
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 |
12544 KB |
Output is correct |
4 |
Correct |
9 ms |
12652 KB |
Output is correct |
5 |
Correct |
9 ms |
12652 KB |
Output is correct |
6 |
Correct |
9 ms |
12524 KB |
Output is correct |
7 |
Correct |
9 ms |
12652 KB |
Output is correct |
8 |
Correct |
9 ms |
12652 KB |
Output is correct |
9 |
Incorrect |
9 ms |
12524 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
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 |
12544 KB |
Output is correct |
4 |
Correct |
9 ms |
12652 KB |
Output is correct |
5 |
Correct |
9 ms |
12652 KB |
Output is correct |
6 |
Correct |
9 ms |
12524 KB |
Output is correct |
7 |
Correct |
9 ms |
12652 KB |
Output is correct |
8 |
Correct |
9 ms |
12652 KB |
Output is correct |
9 |
Incorrect |
9 ms |
12524 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
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 |
12544 KB |
Output is correct |
4 |
Correct |
9 ms |
12652 KB |
Output is correct |
5 |
Correct |
9 ms |
12652 KB |
Output is correct |
6 |
Correct |
9 ms |
12524 KB |
Output is correct |
7 |
Correct |
9 ms |
12652 KB |
Output is correct |
8 |
Correct |
9 ms |
12652 KB |
Output is correct |
9 |
Incorrect |
9 ms |
12524 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |