#include "bits/stdc++.h"
#define F first
#define S second
#define ll long long
#define pii pair<ll,ll>
const ll mxN = 1e5 + 5;
const ll mod = 1e9 + 7;
using namespace std;
struct edge{
int first,id,second;
};
vector<vector<edge>>v,tr;
int p[mxN];
int ans[mxN];
bool vis[mxN];
int dep[mxN];
void calctr(int u){
vis[u] = 1;
for(auto x : v[u]){
if(vis[x.F]) continue;
tr[x.F].push_back({u,x.id,!x.S});
tr[u].push_back(x);
calctr(x.F);
}
}
int n,m,pr;
int g[mxN],t[mxN];
int ng,nt;
void dfs(int u,int par,int ty,int id){
dep[u] = dep[par] + 1;
for(auto x : tr[u]){
if(x.F == par) continue;
dfs(x.F,u,x.S,x.id);
}
if(g[u]){
if(vis[g[u]]) nt--;
else ng++;
}
if(t[u]){
if(vis[t[u]]) ng--;
else nt++;
}
// cout<<nt<<' '<<ng<<'\n';
vis[u] = 1;
if(p[u] == 0) p[u] = m;
for(auto x : v[u]) if(x.F != par) p[u] = min(dep[x.F],p[u]);
p[par] = p[u];
// cout<<u<<' '<<p[u]<<'\n';
if(p[u] >= dep[u]){
if(ng) ans[id] = ty + 1;
else if(nt) ans[id] = (!ty) + 1;
}
}
signed main(){
// ios_base::sync_with_stdio(0);
// cin.tie(0);
// cout.tie(0);
cin >>n>>m;
v.resize(n + 4);
tr.resize(n + 4);
for(int i = 1;i <= m;i++){
int x,y;
cin >>x>>y;
v[x].push_back({y,i, 0});
v[y].push_back({x,i, 1});
}
cin >>pr;
for(int i = 0;i < pr;i++){
int x,y;
cin >>x>>y;
g[x] = y;
t[y] = x;
}
calctr(1);
// cout<<"TEST\n";
memset(vis,0,sizeof vis);
dfs(1,0,0,0);
for(int i = 1;i <= m;i++) cout<<(ans[i] == 0 ? 'B' : (ans[i] == 2 ? 'R' : 'L'));
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
