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Submission #999038

# Submission time Handle Problem Language Result Execution time Memory
999038 2024-06-15T05:31:58 Z vjudge1 Sumtree (INOI20_sumtree) C++17
0 / 100
 50 ms 19792 KB 
#include <bits/stdc++.h>

using namespace std;

#define int long long

const int MXN = 3e5 + 5;
const int mod = 1e9 + 7;

int n, r;
vector<int> adj[MXN];
int f[MXN];

int pw(int a, int b, int c)
{
	a %= c;
	int res = 1;
	while (b)
	{
		if (b & 1) res = (res * a) % mod;
		a = (a * a) % mod;
		b >>= 1;
	}
	return res;
}

int nck(int n, int k)
{
	if (min(n, k) < 0 || k > n) return 0;
	return (f[n] * pw((f[n - k] * f[k]) % mod, mod - 2, mod)) % mod;
}

signed main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	f[0] = 1;
	for (int i = 1; i < MXN; i++) f[i] = (f[i - 1] * i) % mod;
	cin >> n >> r;
	for (int i = 1; i < n; i++)
	{
		int u, v;
		cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	int q, res = 0;
	cin >> q;
	cout << nck(n + r - 1, r) << '\n';
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:47:9: warning: unused variable 'res' [-Wunused-variable]
   47 |  int q, res = 0;
      |         ^~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 45 ms 19540 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 4 ms 9816 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 47 ms 19520 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 50 ms 19792 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Incorrect 45 ms 19540 KB Output isn't correct
2 Halted 0 ms 0 KB -