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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#790422 | #3846. Link-Cut Tree | Yurily# | AC ✓ | 853ms | 26812kb | C++20 | 2.5kb | 2024-11-28 11:46:29 | 2024-11-28 11:46:30 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int MAX=1e5+5;
vector<int> g[MAX];
struct edge{
int from,to;
};
edge e[MAX];
int n,m,fa[MAX];
stack<int> st;
bool flag,vis[MAX];
map<pair<int,int>,int> edg;
int ans[MAX],cnt,anse[MAX];
void dfs(int u,int fr){
if(flag)
return;
st.push(u);
for(auto i=g[u].begin();i!=g[u].end();++i){
int v=(*i);
if(v==fr||v==u)
continue;
if(flag)
return;
if(vis[v]){
flag=1;
while(st.top()!=v){
ans[++cnt]=st.top();
st.pop();
}
ans[++cnt]=v;
return;
}
else{
vis[v]=1;
dfs(v,u);
}
}
if(flag)
return;
st.pop();
}
int findf(int x){
if(fa[x]==x)
return x;
fa[x]=findf(fa[x]);
return fa[x];
}
void solve(){
edg.clear();
while(!st.empty())
st.pop();
cnt=0;
flag=0;
cin>>n>>m;
for(int i=1;i<=n;++i){
fa[i]=i;
}
memset(vis,0,sizeof(bool)*(n+1));
for(int i=1;i<=n;++i)
g[i].clear();
for(int i=1;i<=m;++i){
cin>>e[i].from>>e[i].to;
if(!edg[make_pair(e[i].from,e[i].to)]){
edg[make_pair(e[i].from,e[i].to)]=i;
edg[make_pair(e[i].to,e[i].from)]=i;
}
}
int tot=0;
for(int i=1;i<=m;++i){
tot=i;
int r1=findf(e[i].from),r2=findf(e[i].to);
if(r1!=r2){
fa[r2]=r1;
}
else{
break;
}
}
for(int i=1;i<=tot;++i){
g[e[i].from].push_back(e[i].to);
g[e[i].to].push_back(e[i].from);
}
for(int i=1;i<=n;++i){
if(!vis[i]&&!flag){
vis[i]=1;
dfs(i,0);
}
}
if(flag){
anse[1]=edg[make_pair(ans[1],ans[2])];
for(int i=2;i<=cnt-1;++i){
anse[i]=edg[make_pair(ans[i],ans[i+1])];
}
anse[cnt]=edg[make_pair(ans[cnt],ans[1])];
sort(anse+1,anse+1+cnt);
cout<<anse[1];
for(int i=2;i<=cnt;++i)
cout<<" "<<anse[i];
cout<<"\n";
}
else{
cout<<"-1\n";
}
}
int main(){
// freopen("in.txt","r",stdin);
// freopen("out.txt","w",stdout);
ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
int T;
cin>>T;
while(T--){
solve();
}
}
詳細信息
Test #1:
score: 100
Accepted
time: 1ms
memory: 3636kb
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: 853ms
memory: 23628kb
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: 516ms
memory: 26812kb
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