#include <bits/stdc++.h>
#define s second
#define f first
#define pb push_back
using namespace std;
const int N = 100005;
int tin[N],low[N],a[N],b[N],ID[N],O[N][1005],C[N][1005];
vector <int> adj[N],vec[N];
bool bridge[N],vis[N];
int k,idx,cnt;
void dfs(int x,int par){
vis[x] = 1;
tin[x] = low[x] = cnt++;
for (int id: adj[x]){
int to = b[id];
if (to == x) to = a[id];
if (to == par) continue;
if (vis[to]){
low[x] = min(low[x], tin[to]);
}else{
dfs(to,x);
low[x] = min(low[x], low[to]);
if (low[to] > tin[x])
bridge[id] = 1;
}
}
}
void dfs1(int x){
ID[x] = idx;
vis[x] = 1;
for (int id: adj[x]){
int to = b[id];
if (to == x) to = a[id];
if (!vis[to] && !bridge[id]) dfs1(to);
else if (!vis[to] && bridge[id]) vec[idx].pb(to);
}
}
void dfs2(int x,int par){
vis[x] = 1;
tin[x] = tin[par] + 1;
for (int to: adj[x]){
if (vis[to]) continue;
dfs2(to,x);
for (int j = 1; j <= k; j++){
O[x][j] += O[to][j];
C[x][j] += C[to][j];
}
}
}
int main (){
ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
int n,m;
cin>>n>>m;
for (int i = 1; i <= m; i++){
cin>>a[i]>>b[i];
adj[a[i]].pb(i);
adj[b[i]].pb(i);
}
for (int i= 1; i <= n; i++)
if (!vis[i]) dfs(i,i);
for (int i= 1; i <= n; i++)
vis[i] = 0;
idx = 0;
for (int i = 1; i <= n; i++){
if (vis[i]) continue;
idx++;
dfs1(i);
}
for (int i = 1; i <= n; i++)
adj[i].clear();
for (int i = 1; i <= n; i++)
for (int x: vec[i]){
if (i == ID[x]) continue;
adj[i].pb(ID[x]);
// cout<<i<<" "<<ID[x]<<endl;
adj[ID[x]].pb(i);
}
cin>>k;
for (int i = 1; i <= k; i++){
int x,y;
cin>>x>>y;
O[ID[x]][i]++;
C[ID[y]][i]++;
}
for (int i = 1; i <= n; i++)
vis[i] = tin[i] = 0;
for (int i = 1; i <= n; i++)
if (!vis[i]) dfs2(i,i);
for (int i = 1; i <= m; i++){
if (bridge[i] == 0) cout<<'B';
else{
int x = ID[a[i]],y = ID[b[i]],o=0,c=0;
if (tin[x] > tin[y]){
for (int j = 1; j <= k; j++)
if (O[x][j] && !C[x][j]) o++;
else if (!O[x][j] && C[x][j]) c++;
if(o && !c) cout<<'R';
else if (!o && c) cout<<'L';
else cout<<'B';
}else{
for (int j = 1; j <= k; j++)
if (O[y][j] && !C[y][j]) o++;
else if (!O[y][j] && C[y][j]) c++;
if(o && !c) cout<<'L';
else if (!o && c) cout<<'R';
else cout<<'B';
}
}
}
}
Compilation message
oneway.cpp: In function 'int main()':
oneway.cpp:101:25: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
101 | vis[i] = tin[i] = 0;
| ~~~~~~~^~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5076 KB |
Output is correct |
2 |
Correct |
3 ms |
5076 KB |
Output is correct |
3 |
Correct |
3 ms |
5204 KB |
Output is correct |
4 |
Correct |
5 ms |
9172 KB |
Output is correct |
5 |
Correct |
6 ms |
10964 KB |
Output is correct |
6 |
Correct |
3 ms |
5076 KB |
Output is correct |
7 |
Correct |
7 ms |
10964 KB |
Output is correct |
8 |
Correct |
8 ms |
9572 KB |
Output is correct |
9 |
Incorrect |
3 ms |
5168 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5076 KB |
Output is correct |
2 |
Correct |
3 ms |
5076 KB |
Output is correct |
3 |
Correct |
3 ms |
5204 KB |
Output is correct |
4 |
Correct |
5 ms |
9172 KB |
Output is correct |
5 |
Correct |
6 ms |
10964 KB |
Output is correct |
6 |
Correct |
3 ms |
5076 KB |
Output is correct |
7 |
Correct |
7 ms |
10964 KB |
Output is correct |
8 |
Correct |
8 ms |
9572 KB |
Output is correct |
9 |
Incorrect |
3 ms |
5168 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
2 ms |
5076 KB |
Output is correct |
2 |
Correct |
3 ms |
5076 KB |
Output is correct |
3 |
Correct |
3 ms |
5204 KB |
Output is correct |
4 |
Correct |
5 ms |
9172 KB |
Output is correct |
5 |
Correct |
6 ms |
10964 KB |
Output is correct |
6 |
Correct |
3 ms |
5076 KB |
Output is correct |
7 |
Correct |
7 ms |
10964 KB |
Output is correct |
8 |
Correct |
8 ms |
9572 KB |
Output is correct |
9 |
Incorrect |
3 ms |
5168 KB |
Output isn't correct |
10 |
Halted |
0 ms |
0 KB |
- |