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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 |
---|---|---|---|---|---|---|---|---|---|
#296598 | #6307. Chase Game 2 | HJR | WA | 14ms | 3556kb | C++23 | 2.0kb | 2024-01-03 10:53:11 | 2024-01-03 10:53:12 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
#define endl "\n"
#define debug(x) cout<<#x<<": "<<x<<endl
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
using ll=long long;
using ull=unsigned long long;
#define int long long
void solve(){
int n;
cin>>n;
vector<vector<int>> adj(n+1);
vector<int> du(n+1);
for(int i=0;i<n-1;i++){
int u,v;
cin>>u>>v;
adj[u].push_back(v);
adj[v].push_back(u);
du[u]++;
du[v]++;
}
int le=0;
for(int i=1;i<=n;i++){
if(du[i]==1)
le++;
}
int dep=0;
int ed=1;
vector<bool> vis1(n+1),vis2(n+1);
queue<int> q;
q.push(1);
vis1[1]=1;
while(!q.empty()){
int u=q.front();
q.pop();
ed=u;
for(auto x:adj[u]){
if(vis1[x])
continue;
vis1[x]=1;
q.push(x);
}
}
q.push(ed);
vis2[ed]=1;
while(!q.empty()){
int cn=q.size();
for(int i=0;i<cn;i++){
int u=q.front();
q.pop();
for(auto x:adj[u]){
if(vis2[x])
continue;
vis2[x]=1;
q.push(x);
}
}
dep++;
}
// debug(dep);
vector<int> lv(n+1);
auto dfs=[&](auto self,int u,int la)->void{
for(auto x:adj[u]){
if(x==la)
continue;
if(adj[x].size()==1)
lv[u]++;
self(self,x,u);
}
};
dfs(dfs,ed,0);
int res=(le+1)/2;
for(int i=1;i<=n;i++){
if(lv[i]>le/2){
res=lv[i];
break;
}
}
if(dep<=3){
cout<<-1<<endl;
}
else{
cout<<res<<endl;
}
}
signed main(){
ios::sync_with_stdio(0);
cout.tie(0);
cin.tie(0);
int t;
cin>>t;
while(t--){
solve();
}
}
详细
Test #1:
score: 100
Accepted
time: 1ms
memory: 3556kb
input:
4 2 1 2 4 1 2 2 3 3 4 4 1 2 2 3 2 4 5 1 2 2 3 3 4 3 5
output:
-1 1 -1 2
result:
ok 4 number(s): "-1 1 -1 2"
Test #2:
score: 0
Accepted
time: 7ms
memory: 3504kb
input:
10000 4 1 2 1 3 3 4 4 1 2 1 3 1 4 4 1 2 2 3 1 4 5 1 2 2 3 1 4 4 5 5 1 2 2 3 3 4 4 5 4 1 2 2 3 2 4 5 1 2 1 3 2 4 2 5 4 1 2 2 3 1 4 5 1 2 1 3 2 4 1 5 5 1 2 2 3 3 4 2 5 5 1 2 1 3 2 4 2 5 4 1 2 1 3 3 4 5 1 2 1 3 3 4 1 5 4 1 2 1 3 1 4 5 1 2 1 3 3 4 3 5 5 1 2 2 3 3 4 3 5 4 1 2 1 3 2 4 5 1 2 2 3 2 4 3 5 5 ...
output:
1 -1 1 1 1 -1 2 1 2 2 2 1 2 -1 2 2 1 2 2 1 1 1 -1 2 2 2 1 -1 1 1 2 1 1 -1 1 2 1 1 1 -1 1 1 2 2 2 1 1 1 -1 1 2 1 1 2 1 2 1 1 2 -1 -1 -1 2 2 2 1 1 1 2 2 2 -1 1 2 -1 1 1 -1 2 -1 -1 1 2 2 2 1 1 1 1 1 1 1 1 1 2 -1 1 1 2 -1 2 1 1 1 -1 2 -1 1 -1 -1 2 -1 2 1 2 2 1 1 1 1 2 1 1 1 1 -1 2 1 2 1 1 1 1 1 1 1 2 -1...
result:
ok 10000 numbers
Test #3:
score: -100
Wrong Answer
time: 14ms
memory: 3556kb
input:
10000 9 1 2 2 3 3 4 4 5 1 6 6 7 5 8 7 9 9 1 2 2 3 2 4 1 5 2 6 4 7 6 8 1 9 9 1 2 2 3 1 4 4 5 5 6 4 7 2 8 1 9 10 1 2 2 3 1 4 3 5 3 6 2 7 6 8 6 9 6 10 10 1 2 1 3 3 4 2 5 1 6 5 7 4 8 2 9 7 10 10 1 2 2 3 2 4 1 5 3 6 6 7 5 8 4 9 9 10 9 1 2 2 3 2 4 1 5 3 6 2 7 1 8 2 9 9 1 2 1 3 2 4 1 5 3 6 3 7 7 8 8 9 10 1...
output:
1 3 3 3 2 2 3 2 3 2 3 2 3 2 3 3 3 2 3 2 3 2 3 3 2 2 3 3 3 3 3 3 2 3 3 3 4 3 3 3 2 3 3 3 3 3 2 3 3 3 3 3 3 2 3 2 3 2 2 3 3 4 3 4 3 3 2 2 3 2 2 2 3 3 2 3 3 2 3 3 3 3 2 3 2 2 3 3 3 3 2 3 3 2 3 3 3 3 3 2 3 2 2 3 5 3 3 2 2 3 2 3 4 2 5 3 2 3 3 2 3 2 3 3 3 3 2 2 3 3 3 2 3 3 3 3 3 3 2 3 3 2 2 4 3 3 3 3 2 3 ...
result:
wrong answer 79th numbers differ - expected: '4', found: '3'