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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 2HJRWA 14ms3556kbC++232.0kb2024-01-03 10:53:112024-01-03 10:53:12

Judging History

你现在查看的是最新测评结果

  • [2024-01-03 10:53:12]
  • 评测
  • 测评结果:WA
  • 用时:14ms
  • 内存:3556kb
  • [2024-01-03 10:53:11]
  • 提交

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'