#include <bits/stdc++.h>
using namespace std;
int N, M, P;
vector<vector<pair<int, int>>> G;
vector<pair<int, int>> E;
vector<int> req;
int TIMER = -1;
stack<int> S;
vector<int> tin, low;
int cc = -1;
vector<int> C;
void make_comp(int last) {
cc++;
int v = -1;
do {
v = S.top();
S.pop();
C[v] = cc;
} while (v != last);
}
void dfs(int v, int pidx) {
S.push(v);
tin[v] = low[v] = ++TIMER;
for (auto [u, eidx] : G[v]) {
if (eidx == pidx) continue;
if (tin[u] == -1) {
dfs(u, eidx);
req[v] += req[u];
}
low[v] = min(low[v], low[u]);
}
if (low[v] == tin[v]) make_comp(v);
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
cin >> N >> M;
G.resize(N);
for (int i = 0; i < M; i++) {
int v, u; cin >> v >> u; v--, u--;
G[v].push_back({u, i});
G[u].push_back({v, i});
E.push_back({v, u});
}
req.resize(N);
cin >> P;
for (int i = 0; i < P; i++) {
int v, u; cin >> v >> u; v--, u--;
req[v]++, req[u]--;
}
C.resize(N);
tin.assign(N, -1);
low.assign(N, -1);
dfs(0, -1);
string ans(M, '?');
for (int i = 0; i < M; i++) {
auto [v, u] = E[i];
if (C[v] == C[u]) { ans[i] = 'B'; continue; }
if (tin[v] < tin[u]) {
if (req[u] > 0) ans[i] = 'L';
else if (req[u] == 0) ans[i] = 'B';
else ans[i] = 'R';
} else {
if (req[v] > 0) ans[i] = 'R';
else if (req[v] == 0) ans[i] = 'B';
else ans[i] = 'L';
}
}
cout << ans << endl;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
