#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
const int N=100100;
int n,m,p,x,y;
vector<vector<pair<int,int>>>graph(N);
vector<pair<int,int>>directions(N);
vector<int>dp(N);
vector<int>bridges(N);
int text[N];
int visitados[N];
int dfstree(int pos, int prev, int altura){
//cout<<pos<<" POS"<<endl;
visitados[pos]=1;
dp[pos]=altura;
for(int i=0;i<int(graph[pos].size());i++){
if(graph[pos][i].second==prev){
continue;
}
if(visitados[graph[pos][i].first]==2){
continue;
}
if(visitados[graph[pos][i].first]==1){
dp[pos]=min(dp[graph[pos][i].first],dp[pos]);
continue;
}
dp[pos]=min(dfstree(graph[pos][i].first, graph[pos][i].second,altura+1),dp[pos]);
}
visitados[pos]=2;
if(prev != -1 && dp[pos]>=altura){
//cout<<prev<<endl;
bridges[prev]=1;
}
return dp[pos];
}
int dfs(int pos,int finalpos){
visitados[pos]=1;
if(pos==finalpos){
return 1;
}
//cout<<pos<<" POOOOOS"<<endl;
for(int i=0;i<int(graph[pos].size());i++){
//cout<<visitados[pos]<<endl;
if (visitados[graph[pos][i].first]==1){
continue;
}
int index=graph[pos][i].second;
int passfinal=dfs(graph[pos][i].first,finalpos);
if(passfinal==1){
if(bridges[index]==1){
if(directions[index].first==pos && directions[index].second==graph[pos][i].first){
text[index]=1;
}else{
text[index]=2;
}
}
return 1;
}
}
return 0;
}
int main(){
cin>>n >> m;
for(int i=1;i<=m;i++){
int a,b; cin >> a >> b;
graph[a].pb({b,i});
graph[b].pb({a,i});
directions[i]={a,b};
}
for(int i = 0 ; i <= m ; i ++ )bridges[i] = 0;
memset(visitados,-1,sizeof(visitados));
for(int i = 1 ; i<= n ; i ++){
if(vis[i] == -1)dfstree(i, -1, 1);
}
cin >> p;
memset(text,-1, sizeof text );
while(p--){
cin>>x>>y;
memset(visitados,-1,sizeof(visitados));
dfs(x,y);
}
for(int i=1;i<=m;i++){
if(text[i]==1){
cout<<"R";
continue;
}
if(text[i]==2){
cout<<"L";
continue;
}
cout<<"B";
}
cout<<endl;
}
Compilation message
oneway.cpp: In function 'int main()':
oneway.cpp:92:12: error: 'vis' was not declared in this scope
92 | if(vis[i] == -1)dfstree(i, -1, 1);
| ^~~
