#include <bits/stdc++.h>
#define pb push_back
#define eb emplace_back
#define all(a) begin(a), end(a)
#define F first
#define S second
using namespace std;
int const N = 1005;
int n, m, p;
vector<vector<pair<int, int>>> adj;
vector<set<pair<int, int>>> vp;
vector<pair<int, int>> edges;
vector<vector<pair<int, int>>> adjtree;
void load() {
cin >> n >> m;
adj.resize(n);
for (int i = 0; i < m; ++i) {
int u, v;
cin >> u >> v;
--u; --v;
edges.eb(u, v);
adj[u].eb(v, i);
adj[v].eb(u, i);
}
vp.resize(n);
adjtree.resize(n);
cin >> p;
for (int i = 0; i < p; ++i) {
int a, b;
cin >> a >> b;
--a; --b;
if (a == b) continue;
vp[a].insert({i, 0});
vp[b].insert({i, 1});
}
}
int dfsnum[N], dfsmin[N];
int cnt = 0;
void dfsspan(int ver, int pi) {
dfsnum[ver] = dfsmin[ver] = cnt++;
for (auto [u, ind] : adj[ver]) {
if (ind == pi) continue;
if (dfsnum[u] != -1) {
dfsmin[ver] = min(dfsmin[ver], dfsmin[u]);
} else {
dfsspan(u, ind);
dfsmin[ver] = min(dfsmin[ver], dfsmin[u]);
adjtree[ver].eb(u, dfsmin[u] > dfsnum[ver] ? ind : -1);
}
}
}
string ans;
set<pair<int, int>> dfs(int ver) {
set<pair<int, int>> cur = vp[ver];
for (auto [u, t] : adjtree[ver]) {
auto tmp = dfs(u);
if (t != -1 && !tmp.empty()) {
if (tmp.begin()->S ^ (edges[t] == pair{ver, u})) {
ans[t] = 'L';
} else {
ans[t] = 'R';
}
}
if (size(cur) < size(tmp)) cur.swap(tmp);
for (auto [x, y] : tmp) {
auto it = cur.find({x, !y});
if (it != cur.end()) {
cur.erase(it);
} else {
cur.insert({x, y});
}
}
}
return cur;
}
void solve() {
memset(dfsnum, -1, sizeof dfsnum);
dfsspan(0, -1);
ans = string(m, 'B');
dfs(0);
cout << ans << '\n';
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
load();
solve();
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
212 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
