#include<bits/stdc++.h>
using namespace std;
int n, m, p, u, v, lead[100005], low[100005], num[100005], d = 0, cnt = 0, ans[100005], timer = 0, q, val[100005];
vector<pair<int,int>> adj[100005];
vector<pair<int,int>> adj2[100005], edge;
stack<int> s;
void dfs(int u, int id) {
low[u] = num[u] = ++d;
s.push(u);
for (pair<int, int> W: adj[u]) {
int node = W.first;
if(W.second == id) continue;
if(num[node] != 0) low[u] = min(low[u], num[node]);
else {
dfs(node, W.second);
low[u] = min(low[u], low[node]);
}
}
if(low[u] == num[u]) {
cnt++;
while(s.top() != u) lead[s.top()] = cnt, s.pop();
lead[s.top()] = cnt, s.pop();
}
}
void cal(int u, int par) {
for (pair<int, int> node: adj2[u]) {
if(node.first == par) continue;
cal(node.first, u);
val[u] += val[node.first];
}
}
void get_ans(int u, int par) {
for (pair<int, int> node: adj2[u]) {
if(node.first == par) continue;
int x, y;
x = u, y = node.first;
int id = node.second;
if(val[node.first] < 0) {
if(lead[edge[id].first] == x && lead[edge[id].second] == y) ans[id+1] = 1;
else ans[id+1] = 2;
}
else {
if(lead[edge[id].first] == x && lead[edge[id].second] == y) ans[id+1] = 2;
else ans[id+1] = 1;
}
get_ans(node.first, u);
}
}
void solve() {
cin >> n >> m;
for (int i = 1; i <= m; i++) {
cin >> u >> v;
edge.push_back({u,v});
adj[u].push_back({v,i});
adj[v].push_back({u,i});
}
dfs(1, -1);
int idx = 0;
for (pair<int, int> i: edge) {
if(lead[i.first] != lead[i.second]) adj2[lead[i.first]].push_back({lead[i.second], idx}), adj2[lead[i.second]].push_back({lead[i.first],idx});
idx++;
}
cin >> q;
while(q--) {
cin >> u >> v;
u = lead[u];
v = lead[v];
val[u]++;
val[v]--;
}
cal(1,-1);
get_ans(1, -1);
for (int i = 1; i <= m; i++) if(ans[i] == 0) cout << 'B'; else if(ans[i] == 1) cout << 'R'; else cout << 'L';
}
signed main() {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if(fopen("input.inp","r")){
freopen("input.inp", "r", stdin);
freopen("output.out", "w", stdout);
}
int t = 1;
// cin >> t;
while(t--) {
solve();
}
}
Compilation message
oneway.cpp: In function 'int main()':
oneway.cpp:80:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
80 | freopen("input.inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
oneway.cpp:81:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
81 | freopen("output.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
6748 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
6748 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
6748 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
