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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
#213612#2715. 8.4t4ThySecret2053ms5920kbC++111.8kb2024-11-12 21:46:012024-11-12 23:56:46

answer

#include <bits/stdc++.h>

using namespace std;

// #define int long long
// #define x first
// #define y second
#define File(a) freopen(a".in", "r", stdin), freopen(a".out", "w", stdout)

inline void debug() { cerr << '\n'; }
template<typename Type, typename... Other>
inline void debug(const Type& x, const Other&... y) { cerr << x << ' '; debug(y...); }
#define DEBUG(a...) cerr << "[" << #a << "] = ", debug(a);

typedef long long LL;
typedef pair<int, int> PII;

const int N = 200010;
const int INF = 0x3f3f3f3f;
const int mod = 1e9 + 7;

template<typename Type>
inline void read(Type &res)
{
    res = 0;
    int ch = getchar(), flag = 0;
    while (!isdigit(ch)) flag |= ch == '-', ch = getchar();
    while (isdigit(ch)) res = (res << 3) + (res << 1) + (ch ^ 48), ch = getchar();
    res = flag ? -res : res;
}
template<typename Type, typename... Other>
inline void read(Type &res, Other&... y) { read(res), read(y...); }

bool vis[N];
vector<int> e[N];
int n;
inline void view_all(vector<int> &cur,int x,int fa)
{
    cur.push_back(x);
    for(int p: e[x])
    {
        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(auto w : cur)
    {
        int res = 1;
        vis[w] = 1;
        for(auto p: e[w])
        {
            if (vis[p]) continue;
            res = 1ll * res * calc(p) % mod;
        }
        vis[w] = 0;
        ans = (ans + res) % mod;
    }
    return ans;
}
inline int get_ans()
{
    return calc(1);
}

signed main()
{
    read(n);
    for (int i = 1; i < n; i ++)
    {
        int a, b; read(a, b);
        e[a].push_back(b), e[b].push_back(a);
    }
    cout << get_ans() << '\n';
    return 0;
}

详细

小提示:点击横条可展开更详细的信息

Test #1:

score: 10
Accepted
time: 39ms
memory: 5920kb

input:

10
1 2
1 3
3 4
3 5
3 6
3 7
1 8
5 9
5 10

output:

227506

result:

ok found '227506.00000', expected '227506.00000', error '0.00000'

Test #2:

score: 10
Accepted
time: 14ms
memory: 5920kb

input:

10
1 2
1 3
3 4
4 5
5 6
4 7
5 8
8 9
8 10

output:

70140

result:

ok found '70140.00000', expected '70140.00000', error '0.00000'

Test #3:

score: 0
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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
Time Limit Exceeded

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...

output:


result: