#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define pb push_back
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
ll MOD = 1e9 + 7;
ll mod(ll x, ll m = MOD){return (x + m)%m;}
const int nax= 2e5 + 5;
const int rax= 3e5 + 5;
ll fact[2 * rax];
ll binpow(ll a, ll b, ll m= MOD)
{
ll res = 1ll;
while(b)
{
if(b & 1)
res = mod(res * 1ll * a);
a = mod(a * 1ll * a);
b /= 2ll;
}
return res;
}
ll inv(ll x, ll m = MOD)
{
return binpow(x, m - 2ll, m);
}
ll C(int a, int b)
{
return mod(fact[a] * inv(mod(fact[a - b] * fact[b])));
}
ll formula(int s, int k)
{
return C(s + k, k);
}
int n, r;
vector<int> adj[nax];
void solve()
{
cin >> n >> r;
for(int i =1; i < n; i++)
{
int a, b;
cin >> a >> b;
adj[a].pb(b);
adj[b].pb(a);
}
cout << formula(r, n - 1);
int q; cin >> q;
while(q--)
{
int t; cin >> t;
if(t == 1)
{
}
else
{
}
}
}
int32_t main()
{
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
fact[0] = 1ll;
for(int i = 1; i < rax; i++)
fact[i] = mod(fact[i - 1] * 1ll * i);
int tt = 1;
while(tt--)
solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
54 ms |
13592 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
6 ms |
7252 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
67 ms |
13660 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
72 ms |
14500 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
54 ms |
13592 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |