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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#96150#6307. Chase Game 2xuzhihaodedie#WA 12ms6440kbC++201.1kb2023-04-13 14:13:032023-04-13 14:13:04

Judging History

你现在查看的是最新测评结果

  • [2023-08-10 23:21:45]
  • System Update: QOJ starts to keep a history of the judgings of all the submissions.
  • [2023-04-13 14:13:04]
  • 评测
  • 测评结果：WA
  • 用时：12ms
  • 内存：6440kb
查看
  • [2023-04-13 14:13:03]
  • 提交

answer

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define x first
#define y second
#define PII pair<int,int>
const int mod=998244353;
const int N=1e5+100;
vector<int>g[N];
int res,ans;
int d[N];
void dfs(int u,int fa)
{
	if(d[u]==1)	return;
	int t=0;
	for(int j : g[u])
	{
		if(j==fa)	continue;
		if(d[j]==1)	t++;
		dfs(j,u);
	}
	ans+=max(0ll,2*t-res);
}
void solve(){
	int n;
	scanf("%lld",&n);
	for(int i=1;i<=n;i++)	g[i].clear(),d[i]=0;
	for(int i=1;i<n;i++)
	{
		int u,v;
		scanf("%lld%lld",&u,&v);
		g[u].push_back(v),g[v].push_back(u);
		d[u]++,d[v]++;
	}
	res=0;
	for(int i=1;i<=n;i++)
		if(d[i]==1)	res++;
	if(res>=n-1)
	{
		puts("-1");
		return;
	}
	ans=res>>1;
	for(int i=1;i<=n;i++)
		if(d[i]>1)
		{
			dfs(i,-1);
			break;
		}
	printf("%lld\n",ans);
}
signed main() {
	int T=1;
//	freopen("C:\\Users\\86153\\Desktop\\data.in.txt","r",stdin); //´ÓÎļþÖлñÈ¡ÊäÈëÁ÷
//	freopen("C:\\Users\\86153\\Desktop\\data1.out.txt","w",stdout); //°ÑÊä³öתµ½ÎļþÖÐ
	//init();
	cin>>T;
	while(T--) {
		solve();
	}
	//return 0;
}
Source code, Language: C++20

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 2ms
memory: 6440kb

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: 9ms
memory: 6008kb

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: 12ms
memory: 6172kb

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
2
2
3
2
1
3
2
2
2
3
2
3
2
2
2
2
2
2
2
3
2
3
2
2
2
2
3
2
3
2
2
2
3
2
3
5
2
3
2
2
2
2
2
2
3
2
3
2
2
2
3
2
1
3
1
2
2
2
3
2
3
2
5
2
2
2
2
2
1
2
2
3
2
2
2
3
2
5
2
2
3
2
3
2
2
2
3
3
3
2
2
3
2
2
3
2
3
2
2
2
2
2
3
7
2
2
1
2
3
2
2
4
2
6
2
1
2
2
2
3
2
2
3
3
3
2
1
3
3
2
2
2
2
2
2
3
2
2
3
3
2
2
3
2
3
2
3
2
2
...

result:

wrong answer 2nd numbers differ - expected: '3', found: '2'
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