QOJ.ac
QOJ
| ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
|---|---|---|---|---|---|---|---|---|---|
| #203918 | #3846. Link-Cut Tree | ushg8877 | AC ✓ | 137ms | 10984kb | C++20 | 1.1kb | 2023-10-06 22:09:26 | 2023-10-06 22:09:26 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define MP make_pair
mt19937 rnd(time(0));
const int MAXN=1e5+5;
int n,m;
int eu[MAXN],ev[MAXN],fa[MAXN];
vector<int> edg[MAXN];int deg[MAXN];
bool used[MAXN];
int find(int x){
while(x^fa[x]) x=fa[x]=fa[fa[x]];
return x;
}
void solve(){
cin>>n>>m;
for(int i=1;i<=n;i++) fa[i]=i,edg[i].clear();
for(int i=1;i<=m;i++) cin>>eu[i]>>ev[i],used[i]=false;
for(int i=1;i<=m;i++) {
edg[eu[i]].push_back(i);
edg[ev[i]].push_back(i);used[i]=true;
if(find(eu[i])!=find(ev[i])) fa[find(eu[i])]=find(ev[i]);
else{
for(int j=1;j<=n;j++) deg[j]=edg[j].size();
queue<int> q;
for(int j=1;j<=n;j++) if(deg[j]==1) q.push(j);
while(!q.empty()){
int u=q.front();q.pop();
for(int i:edg[u]){
int v=(eu[i]==u?ev[i]:eu[i]);
used[i]=false;
if(--deg[v]==1){
q.push(v);
}
}
}
for(int j=1;j<=m;j++) if(used[j]) cout<<j<<" \n"[j==i];
return;
}
}
cout<<"-1"<<endl;
}
int main(){
ios::sync_with_stdio(false);
int _;cin>>_;
while(_--) solve();
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 6044kb
input:
2 6 8 1 2 2 3 5 6 3 4 2 5 5 4 5 1 4 2 4 2 1 2 4 3
output:
2 4 5 6 -1
result:
ok 2 lines
Test #2:
score: 0
Accepted
time: 136ms
memory: 10928kb
input:
1658 9 20 6 4 5 8 1 7 2 3 3 8 3 1 4 8 5 3 7 6 1 6 4 9 4 1 9 3 2 5 4 5 8 9 1 8 4 2 5 7 3 6 14 78 13 12 10 8 2 10 6 13 2 14 13 1 14 10 9 6 2 13 8 3 9 8 5 6 14 12 8 1 9 14 9 5 12 6 5 10 3 12 10 4 8 5 9 10 6 8 1 6 12 4 3 13 1 5 10 3 13 9 10 13 2 5 4 7 7 1 7 6 9 3 2 12 1 10 9 1 1 14 3 1 3 4 11 1 11 6 7 1...
output:
2 5 8 3 5 7 1 3 4 2 3 4 2 3 4 7 13 1 3 4 5 9 3 4 7 12 1 2 3 8 10 11 2 3 5 7 12 13 14 15 16 1 2 3 5 1 2 4 1 3 4 1 2 3 1 2 3 10 11 15 1 5 6 1 5 7 1 2 3 4 -1 1 3 6 -1 1 2 3 5 -1 -1 6 8 9 10 11 16 1 2 6 2 3 4 -1 -1 7 8 12 13 18 -1 1 4 8 12 3 5 10 4 6 8 1 2 3 4 3 5 6 5 8 10 15 4 6 8 -1 1 2 3 5 6 1 3 4 1 ...
result:
ok 1658 lines
Test #3:
score: 0
Accepted
time: 137ms
memory: 10984kb
input:
10 100000 100000 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 9 10 10 11 11 12 12 13 13 14 14 15 15 16 16 17 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 26 26 27 27 28 28 29 29 30 30 31 31 32 32 33 33 34 34 35 35 36 36 37 37 38 38 39 39 40 40 41 41 42 42 43 43 44 44 45 45 46 46 47 47 48 48 49 49 50 50 51 ...
output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 ...
result:
ok 10 lines