#include<bits/stdc++.h>
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
const int N=1e5+5;
int n,m,p;
int val[N],val2[N];
char ans[N];
vector<pair<int,int>> adj[N];
bool vis[N],used[N];
void dfs(int u){
vis[u]=true;
for(auto [v,i]:adj[u]){
if(used[i>>1])continue;
used[i>>1]=true;
if(!vis[v]){
dfs(v);
if(val2[v]>0||!val[v])ans[i>>1]=;
else ans[i>>1]=((val[v]>0)^(i&1))?'L':'R';
val[u]+=val[v];
val2[u]+=val2[v];
}else{
ans[i>>1]='B';
val2[u]++;
val2[v]--;
}
}
}
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
cin >> n >> m;
for(int i=1;i<=m;i++){
int u,v;
cin >> u >> v;
adj[u].emplace_back(v,i<<1);
adj[v].emplace_back(u,i<<1|1);
}
cin >> p;
for(int i=1;i<=p;i++){
int u,v;
cin >> u >> v;
val[u]++;
val[v]--;
}
for(int i=1;i<=n;i++)if(!vis[i])dfs(i);
for(int i=1;i<=m;i++)cout << ans[i];
}
Compilation message
oneway.cpp: In function 'void dfs(int)':
oneway.cpp:16:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
16 | for(auto [v,i]:adj[u]){
| ^
oneway.cpp:21:45: error: expected primary-expression before ';' token
21 | if(val2[v]>0||!val[v])ans[i>>1]=;
| ^
