#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define ii pair<int,int>
#define vii vector<ii>
#define vi vector<int>
#define fi first
#define se second
#define TASK "onewaystreet"
#define ll long long
#define pll pair<ll, ll>
#define vll vector<ll>
#define vpll vector<pll>
#define pb push_back
#define MASK(i) (1 << (i))
#define BIT(x, i) ((x >> (i)) & 1)
using namespace std;
const int oo = 1e9 + 7;
const ll loo = (ll)1e18 + 7;
const int N = 1e5 + 7;
map<pair<int, int>, int> M;
int n, m, p, num[N], low[N], cnt = 0;
vector<int> g[N];
bool visited[N];
string ans;
vector<pair<int, int> > edge;
void visit(int u, int p){
low[u] = num[u] = ++cnt;
for (auto v : g[u]) if (v != p) {
if (num[v]) low[u] = min(low[u], num[v]);
else {
visit(v, u);
low[u] = min(low[u], low[v]);
if (low[v] >= num[v]) {
if (M[{u, v}]){
if (ans[M[{u, v}]] != 'B')
edge.pb({u, v});
}
else if (M[{v, u}]) {
if (ans[M[{v, u}]] != 'B')
edge.pb({v, u});
}
}
}
}
}
map<pair<int, int>, int> M2;
bool dfs(int u, int x){
visited[u] = true;
bool flag = false;
vector<pair<int, int>> candidate;
queue<int> kew;
kew.push(u);
while (!kew.empty()){
int k = kew.front();
kew.pop();
if (k == x) flag = true;
for (auto v : g[k]) if (!visited[v]) {
if (M2[{k, v}] || M2[{v, k}]) {
candidate.pb({k, v});
continue;
}
visited[v] = true;
kew.push(v);
}
}
if (flag) return true;
sort(all(candidate));
candidate.resize(unique(all(candidate)) - candidate.begin());
for (auto v : candidate){
if (dfs(v.se, x) == true){
flag = true;
if (M[{v.fi, v.se}])
ans[M[{v.fi, v.se}]] = 'R';
else if (M[{v.se, v.fi}])
ans[M[{v.se, v.fi}]] = 'L';
}
}
return flag;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
// freopen(TASK".inp", "r", stdin);
// freopen(TASK".out", "w", stdout);
//Nho tat file
cin >> n >> m;
ans.resize(m + 1);
for (int i = 1; i <= m; i++){
int u, v; cin >> u >> v;
if (M[{u, v}] || M[{v, u}]){
ans[i] = 'B';
}
else if (u == v) ans[i] = 'B';
else {
g[u].pb(v);
g[v].pb(u);
}
M[{u, v}] = i;
}
for (int i = 1; i <= n; i++) if (num[i] == 0)
visit(i, i);
for (int i = 1; i <= m; i++) ans[i] = 'B';
for (int i = 0; i < edge.size(); i++){
int u = edge[i].fi, v = edge[i].se;
ans[M[{u, v}]] = ' ';
M2[{u, v}]++;
}
cin >> p;
while (p--){
int x, y; cin >> x >> y;
memset(visited, false, sizeof visited);
dfs(x, y);
}
for (int i = 1; i < ans.size(); i++) cout << ans[i];
return 0;
}
Compilation message
oneway.cpp: In function 'int main()':
oneway.cpp:106:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
106 | for (int i = 0; i < edge.size(); i++){
| ~~^~~~~~~~~~~~~
oneway.cpp:117:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
117 | for (int i = 1; i < ans.size(); i++) cout << ans[i];
| ~~^~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2772 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2772 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
2772 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
