#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define sz(x) (int)x.size()
#define ALL(v) v.begin(),v.end()
#define MASK(k) (1LL << (k))
#define BIT(x, i) (((x) >> (i)) & 1)
#define oo (ll)1e18
#define INF (ll)1e9
#define MOD (ll)(1e9 + 7)
using namespace std;
template<class T1, class T2>
bool maximize(T1 &a, T2 b){if(a < b){a = b; return true;} return false;}
template<class T1, class T2>
bool minimize(T1 &a, T2 b){if(a > b){a = b; return true;} return false;}
template<class T1, class T2>
void add(T1 &a, T2 b){a += b; if(a >= MOD) a -= MOD;}
template<class T1, class T2>
void sub(T1 &a, T2 b){a -= b; if(a < 0) a += MOD;}
template<class T>
void cps(T &v){sort(ALL(v)); v.resize(unique(ALL(v)) - v.begin());}
const int MAX = 1e5 + 10, LOG = 17;
int N, M, T, K;
vector<int> adj[MAX], nadj[MAX];
int timer, low[MAX], num[MAX], gr[MAX], h[MAX], d[MAX][LOG], in[MAX], out[MAX], tmr, ans[MAX];
ll val[MAX];
pair<int, int> edge[MAX];
vector<pair<int, int>> edges, prs;
stack<int> st;
map<pair<int, int>, int> mp;
void tarjan(int u, int p = -1){
low[u] = num[u] = ++timer;
st.push(u);
for(int v: adj[u]){
if(v == p) continue;
if(!num[v]) tarjan(v, u);
minimize(low[u], low[v]);
}
if(low[u] == num[u]){
K++;
while(true){
int v = st.top(); st.pop();
num[v] = low[v] = INF;
gr[v] = K;
if(v == u) break;
}
}
}
void dfs(int u, int p = -1){
in[u] = ++tmr;
edge[tmr] = make_pair(p, u);
for(int v: nadj[u]){
if(v == p) continue;
h[v] = h[u] + 1;
d[v][0] = u;
for(int i = 1; i < LOG; i++) d[v][i] = d[d[v][i - 1]][i - 1];
dfs(v, u);
}
out[u] = tmr;
}
int lca(int u, int v){
if(h[u] < h[v]) swap(u, v);
int delta = h[u] - h[v];
for(int i = 0; i < LOG; i++) if(BIT(delta, i)){
u = d[u][i];
}
if(u == v) return u;
for(int i = LOG - 1; i >= 0; i--) if(d[u][i] != d[v][i]){
u = d[u][i];
v = d[v][i];
}
return d[v][0];
}
void solve(){
cin >> N >> M;
for(int i = 1; i <= M; i++){
int u, v; cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
edges.push_back({u, v});
}
cin >> T;
for(int i = 1; i <= T; i++){
int u, v; cin >> u >> v;
prs.push_back({u, v});
}
for(int i = 1; i <= N; i++) if(!num[i]){
tarjan(i);
}
for(int i = 0; i < sz(edges); i++){
auto o = edges[i];
int u = gr[o.fi], v = gr[o.se];
if(u != v){
mp[make_pair(u, v)] = i;
nadj[u].push_back(v);
nadj[v].push_back(u);
}
}
for(int i = 1; i <= K; i++){
cps(nadj[i]);
}
for(int i = 1; i <= K; i++) if(in[i] == 0){
dfs(i);
}
for(auto o: prs){
int u = gr[o.fi], v = gr[o.se];
int p = lca(u, v);
val[in[u]]++;
val[in[p]]--;
val[in[v]] += MASK(20);
val[in[p]] -= MASK(20);
}
for(int i = K; i >= 1; i--){
val[i] += val[i + 1];
}
for(int i = 2; i <= K; i++){
ll c = val[in[i]] - val[out[i] + 1];
int u = d[i][0], v = i;
if(mp.count(make_pair(u, v))){
int id = mp[make_pair(u, v)];
if(c >= MASK(20)) ans[id] = 1;
else if(c >= 1) ans[id] = 2;
}
else{
int id = mp[make_pair(v, u)];
if(c >= MASK(20)) ans[id] = 2;
else ans[id] = 1;
}
}
for(int i = 0; i < M; i++){
if(!ans[i]) cout << "B";
else if(ans[i] == 1) cout << "R";
else cout << "L";
}
}
int main(){
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen("order.inp","r",stdin);
// freopen("order.out","w",stdout);
int t = 1;
// cin >> t;
while(t--){
solve();
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
5720 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
5720 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
5720 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
