Submission #641632

#	Time	Username	Problem	Language	Result	Execution time	Memory
641632		Itamar	Star Trek (CEOI20_startrek)	C++14	7 / 100	3 ms	2660 KiB

startrek

using namespace std;
#include <iostream>
#include <vector>
#define pi pair<int,int>
#define vi vector<int>
#define ll long long

const int siz = 1e5;
vi f[siz];
ll m = 1e9 + 7;
ll powe(ll a, ll b) {
    if (b == 0)
        return 1;
    ll ans = powe(a, b / 2);
    ans = (ans * ans) % m;
    if (b % 2) {
        ans = (ans * a) % m;
    }
    return ans;
}
int main()
{
    ll n,d;
    cin >> n >> d;

    for (int i = 0; i < n-1; i++) {
        int a, b;
        cin >> a >> b;
        a--, b--;
        f[a].push_back(b);
        f[b].push_back(a);
    }
    ll x = powe(4, d);
    if (x < 0)
        x += m;
    cout << x;
}

// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
// Debug program: F5 or Debug > Start Debugging menu

// Tips for Getting Started: 
//   1. Use the Solution Explorer window to add/manage files
//   2. Use the Team Explorer window to connect to source control
//   3. Use the Output window to see build output and other messages
//   4. Use the Error List window to view errors
//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file

• Subtask 1: 0 / 0
• Subtask 2: 7 / 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