제출 #855458

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
855458		sofijavelkovska	Star Trek (CEOI20_startrek)	C++14	0 / 100	1 ms	2652 KiB

startrek

#include <bits/stdc++.h>
using namespace std;

const int MAXN=1e5, MOD=1e9+7;

vector<int> adj[MAXN+1];

long long power2(long long n)
{
    long long result=1, current=2;
    for (long long i=0; i<64; i++)
    {
        if (n&((long long)1<<i))
            result=result*current%MOD;
        current=current*current%MOD;
    }

    return result;
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    int n, x, y, i;
    long long d;
    cin >> n >> d;
    for (i=0; i<n-1; i++)
    {
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    cout << power2(d);

    return 0;
}

• Subtask 1: 0 / 0
• Subtask 2: 0 / 7
• Subtask 3: 0 / 8
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 20
• Subtask 7: 0 / 20
• Subtask 8: 0 / 15