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 |
---|---|---|---|---|---|---|---|---|---|
#213604 | #2715. 8.4t4 | LazyCat | 0 | 0ms | 0kb | C++ | 1.0kb | 2024-11-12 21:36:50 | 2024-11-12 23:54:51 |
answer
#include<bits/stdc++.h>
using namespace std;
const int maxn=5001;
const int mod=1e9+7;
int n;
bool vis[maxn];
vector<int> e[maxn];
inline void view_all(vector<int> &cur,int x,int fa)
{
cur.push_back(x);
for(int i=0,p;i<sizeof(e[x]);i++,p=e[x][i])
{
if (vis[p]) continue;
if (p == fa) continue;
view_all(cur, p, x);
}
}
inline int calc(int x)
{
vector<int> cur;
int ans = 0;
view_all(cur, x, -1);
for(int w,i;i<=sizeof(cur);i++,w=cur[i])
{
int res = 1;
vis[w] = 1;
for(int p,j=0;j<sizeof(e[w]);j++,p=e[w][j])
{
if (vis[p]) continue;
res = 1ll * res * calc(p) % mod;
}
vis[w] = 0;
ans = (ans + res) % mod;
}
return ans;
}
int main(){
long long ans=0;
cin >> n;
for(int i=1;i<n;i++){
int x,y;
cin >> x >> y;
e[x].push_back(y);
e[y].push_back(x);
}
for(int i=1;i<=n;i++){
ans+=calc(i);
ans%=mod;
}
cout<<ans<<endl;
return 0;
}
详细
小提示:点击横条可展开更详细的信息
Test #1:
score: 0
Runtime Error
input:
10 1 2 1 3 3 4 3 5 3 6 3 7 1 8 5 9 5 10
output:
result:
Test #2:
score: 0
Runtime Error
input:
10 1 2 1 3 3 4 4 5 5 6 4 7 5 8 8 9 8 10
output:
result:
Test #3:
score: 0
Runtime Error
input:
100 1 2 1 3 1 4 3 5 5 6 4 7 7 8 8 9 8 10 3 11 7 12 1 13 5 14 8 15 10 16 7 17 1 18 6 19 10 20 15 21 7...
output:
result:
Test #4:
score: 0
Runtime Error
input:
100 1 2 2 3 3 4 4 5 4 6 6 7 5 8 8 9 8 10 1 11 6 12 4 13 9 14 13 15 7 16 3 17 15 18 17 19 9 20 8 21 4...
output:
result:
Test #5:
score: 0
Runtime Error
input:
100 1 2 2 3 3 4 2 5 2 6 5 7 2 8 4 9 7 10 5 11 11 12 6 13 8 14 13 15 5 16 11 17 16 18 11 19 7 20 19 2...
output:
result:
Test #6:
score: 0
Runtime Error
input:
500 1 2 1 3 3 4 3 5 5 6 1 7 3 8 8 9 4 10 6 11 7 12 2 13 11 14 8 15 7 16 9 17 2 18 3 19 15 20 2 21 20...
output:
result:
Test #7:
score: 0
Runtime Error
input:
500 1 2 1 3 1 4 2 5 5 6 5 7 4 8 8 9 1 10 4 11 8 12 6 13 13 14 13 15 12 16 1 17 10 18 13 19 1 20 1 21...
output:
result:
Test #8:
score: 0
Runtime Error
input:
5000 1 2 1 3 1 4 3 5 3 6 5 7 4 8 4 9 1 10 5 11 6 12 10 13 12 14 14 15 12 16 8 17 14 18 9 19 8 20 20 ...
output:
result:
Test #9:
score: 0
Runtime Error
input:
5000 1 2 1 3 1 4 2 5 1 6 5 7 2 8 5 9 4 10 9 11 10 12 8 13 7 14 13 15 12 16 5 17 9 18 8 19 3 20 4 21 ...
output:
result:
Test #10:
score: 0
Runtime Error
input:
5000 1 2 1 3 1 4 4 5 4 6 3 7 2 8 8 9 6 10 9 11 3 12 3 13 7 14 13 15 4 16 10 17 9 18 10 19 5 20 17 21...