제출 #296126

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
296126		PedroBigMan	Star Trek (CEOI20_startrek)	C++14	7 / 100	1 ms	384 KiB

startrek

#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <string>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <list>
#include <iomanip>
#include <stdlib.h>
#include <time.h>
using namespace std;
typedef long long int ll;
typedef unsigned long long int ull;
typedef long double ld;
#define REP(i,a,b) for(ll i=a; i<b; i++)
#define pb push_back
#define mp make_pair
#define pl pair<ll,ll>
#define ff first
#define ss second
#define whole(x) x.begin(),x.end()
#define DEBUG(i) cout<<"Pedro Is The Master "<<i<<endl
#define INF 5000000000000000000LL
ll mod=1000000007LL;

template<class A=ll> 
void Out(vector<A> a) {REP(i,0,a.size()) {cout<<a[i]<<" ";} cout<<endl;}

template<class A=ll>
void In(vector<A> &a, ll N) {A cur; REP(i,0,N) {cin>>cur; a.pb(cur);}} 

class Matrix
{
    public:
    ll a,b,c,d;
    
    Matrix() {a=1LL; b=0LL; c=0LL; d=1LL;}
    Matrix(ll x, ll y, ll w, ll z) {a=x; b=y; c=w; d=z;}
    
    Matrix operator *(Matrix X)
    {
        Matrix ANS(a*X.a+b*X.c,a*X.b+b*X.d,c*X.a+d*X.c,c*X.b+d*X.d);
        ANS.a%=mod; ANS.b%=mod; ANS.c%=mod; ANS.d%=mod;
        return ANS;
    }
};

Matrix fastexp(Matrix A, ll e)
{
    if(e==0LL) {Matrix id; return id;}
    if(e%2LL==0LL) {Matrix V = fastexp(A,e/2LL); return (V*V);}
    else {Matrix V=fastexp(A,e/2LL); return (V*V*A);}
}

ll fastexp(ll a, ll e)
{
    if(e==0LL) {return 1LL;}
    if(e%2LL==0LL) {ll val = fastexp(a,e/2LL); return ((val*val)%mod);}
    else {ll val=fastexp(a,e/2LL); return ((((val*val)%mod)*a)%mod);}
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    ll N,U; cin>>N>>U;
    vector<vector<ll> > adj; vector<ll> xx; REP(i,0,N) {adj.pb(xx);}
    pl cur;
    REP(i,0,N-1)
    {
        cin>>cur.ff>>cur.ss; cur.ff--; cur.ss--; 
        adj[cur.ff].pb(cur.ss); 
        adj[cur.ss].pb(cur.ff); 
    }
    if(N==2) {ll ans = 4LL*fastexp(4LL,U-1LL); ans%=mod; if(ans<0) {ans+=mod;} cout<<ans<<endl;}
    return 0;
}

• 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