#include <bits/stdc++.h>
#define ld long double
#define endl "\n"
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define pb push_back
#define mp(a,b) make_pair(a,b)
#define ms(v,x) memset(v,x,sizeof(v))
#define all(v) v.begin(),v.end()
#define ff first
#define ss second
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define per(i, a, b) for(int i = b-1; i>=a ; i--)
#define trav(a, x) for(auto& a : x)
#define allin(a , x) for(auto a : x)
#define Unique(v) sort(all(v));v.erase(unique(all(v)),v.end());
#define sz(v) ((int)v.size())
using namespace std;
typedef vector<int> vi;
#define y1 abacaba
//#define left oooooopss
#define db(x) cerr << #x <<" == "<<x << endl;
#define db2(x,y) cerr<<#x <<" == "<<x<<", "<<#y<<" == "<<y<<endl;
#define db3(x,y,z) cerr << #x<<" == "<<x<<", "<<#y<<" == "<<y<<", "<<#z<<" == "<<z<<endl;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef vector<ll> vl;
std::mt19937 rng((int) std::chrono::steady_clock::now().time_since_epoch().count());
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded up
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded down
inline ll mod(ll n, ll m ){ ll ret = n%m; if(ret < 0) ret += m; return ret; }
ll gcd(ll a, ll b){return (b == 0LL ? a : gcd(b, a%b));}
ll exp(ll b,ll e,ll m){
b%=m;
ll ans = 1;
for (; e; b = b * b % m, e /= 2)
if (e & 1) ans = ans * b % m;
return ans;
}
// debug:
void dbg_out() { cerr << endl; }
template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T){
cerr << ' ' << H;
dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr<<"(" << #__VA_ARGS__<<"):" , dbg_out(__VA_ARGS__) , cerr << endl
#else
#define dbg(...) 42
#endif
//
const int N = 100100;
const int M = 1e9 + 7;
// long long?
ll fat[N],inv[N];
ll C(int n,int k){
if(k>n)return 0;
return (fat[n]*inv[k]%M*inv[n-k]%M);
}
void init(){
fat[0] = inv[0] = 1;
for(int i=1;i<N;i++){
fat[i] = (1LL*fat[i-1]*i)%M;
}
inv[N-1] = exp(fat[N-1],M-2,M);
for(int i=N-2;i>=0;i--){
inv[i] = (inv[i+1]*(i+1))%M;
}
}
int32_t main(){
fastio;
init();
int n,k;
cin >> n >> k;
ll res=0;
rep(j,0,k+1){
ll cur = C(n+1,j) * exp(k-j,n,M)%M;
if(j&1)res = (res - cur + M)%M;
else res = (res + cur)%M;
}
cout <<(res + M)%M << endl;
// math -> gcd it all
// Did u check N=1? Did you switch N,M?
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
1868 KB |
Output is correct |
2 |
Correct |
2 ms |
1868 KB |
Output is correct |
3 |
Correct |
2 ms |
1868 KB |
Output is correct |
4 |
Correct |
2 ms |
1884 KB |
Output is correct |
5 |
Correct |
2 ms |
1868 KB |
Output is correct |
6 |
Correct |
2 ms |
1884 KB |
Output is correct |
7 |
Correct |
2 ms |
1888 KB |
Output is correct |
8 |
Correct |
2 ms |
1868 KB |
Output is correct |
9 |
Correct |
2 ms |
1884 KB |
Output is correct |
10 |
Correct |
2 ms |
1880 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
1868 KB |
Output is correct |
2 |
Correct |
2 ms |
1868 KB |
Output is correct |
3 |
Correct |
2 ms |
1868 KB |
Output is correct |
4 |
Correct |
2 ms |
1884 KB |
Output is correct |
5 |
Correct |
2 ms |
1868 KB |
Output is correct |
6 |
Correct |
2 ms |
1884 KB |
Output is correct |
7 |
Correct |
2 ms |
1888 KB |
Output is correct |
8 |
Correct |
2 ms |
1868 KB |
Output is correct |
9 |
Correct |
2 ms |
1884 KB |
Output is correct |
10 |
Correct |
2 ms |
1880 KB |
Output is correct |
11 |
Correct |
2 ms |
1868 KB |
Output is correct |
12 |
Correct |
2 ms |
1868 KB |
Output is correct |
13 |
Correct |
2 ms |
1880 KB |
Output is correct |
14 |
Correct |
2 ms |
1868 KB |
Output is correct |
15 |
Correct |
2 ms |
1868 KB |
Output is correct |
16 |
Correct |
2 ms |
1868 KB |
Output is correct |
17 |
Correct |
2 ms |
1868 KB |
Output is correct |
18 |
Correct |
2 ms |
1868 KB |
Output is correct |
19 |
Correct |
3 ms |
1996 KB |
Output is correct |
20 |
Correct |
2 ms |
1868 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
1868 KB |
Output is correct |
2 |
Correct |
2 ms |
1868 KB |
Output is correct |
3 |
Correct |
2 ms |
1868 KB |
Output is correct |
4 |
Correct |
2 ms |
1884 KB |
Output is correct |
5 |
Correct |
2 ms |
1868 KB |
Output is correct |
6 |
Correct |
2 ms |
1884 KB |
Output is correct |
7 |
Correct |
2 ms |
1888 KB |
Output is correct |
8 |
Correct |
2 ms |
1868 KB |
Output is correct |
9 |
Correct |
2 ms |
1884 KB |
Output is correct |
10 |
Correct |
2 ms |
1880 KB |
Output is correct |
11 |
Correct |
2 ms |
1868 KB |
Output is correct |
12 |
Correct |
2 ms |
1868 KB |
Output is correct |
13 |
Correct |
2 ms |
1880 KB |
Output is correct |
14 |
Correct |
2 ms |
1868 KB |
Output is correct |
15 |
Correct |
2 ms |
1868 KB |
Output is correct |
16 |
Correct |
2 ms |
1868 KB |
Output is correct |
17 |
Correct |
2 ms |
1868 KB |
Output is correct |
18 |
Correct |
2 ms |
1868 KB |
Output is correct |
19 |
Correct |
3 ms |
1996 KB |
Output is correct |
20 |
Correct |
2 ms |
1868 KB |
Output is correct |
21 |
Correct |
2 ms |
1868 KB |
Output is correct |
22 |
Correct |
2 ms |
1868 KB |
Output is correct |
23 |
Correct |
2 ms |
1880 KB |
Output is correct |
24 |
Correct |
2 ms |
1872 KB |
Output is correct |
25 |
Correct |
2 ms |
1868 KB |
Output is correct |
26 |
Correct |
3 ms |
1868 KB |
Output is correct |
27 |
Correct |
2 ms |
1868 KB |
Output is correct |
28 |
Correct |
2 ms |
1884 KB |
Output is correct |
29 |
Correct |
3 ms |
1884 KB |
Output is correct |
30 |
Correct |
3 ms |
1868 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
1868 KB |
Output is correct |
2 |
Correct |
2 ms |
1868 KB |
Output is correct |
3 |
Correct |
2 ms |
1868 KB |
Output is correct |
4 |
Correct |
2 ms |
1884 KB |
Output is correct |
5 |
Correct |
2 ms |
1868 KB |
Output is correct |
6 |
Correct |
2 ms |
1884 KB |
Output is correct |
7 |
Correct |
2 ms |
1888 KB |
Output is correct |
8 |
Correct |
2 ms |
1868 KB |
Output is correct |
9 |
Correct |
2 ms |
1884 KB |
Output is correct |
10 |
Correct |
2 ms |
1880 KB |
Output is correct |
11 |
Correct |
2 ms |
1868 KB |
Output is correct |
12 |
Correct |
2 ms |
1868 KB |
Output is correct |
13 |
Correct |
2 ms |
1880 KB |
Output is correct |
14 |
Correct |
2 ms |
1868 KB |
Output is correct |
15 |
Correct |
2 ms |
1868 KB |
Output is correct |
16 |
Correct |
2 ms |
1868 KB |
Output is correct |
17 |
Correct |
2 ms |
1868 KB |
Output is correct |
18 |
Correct |
2 ms |
1868 KB |
Output is correct |
19 |
Correct |
3 ms |
1996 KB |
Output is correct |
20 |
Correct |
2 ms |
1868 KB |
Output is correct |
21 |
Correct |
2 ms |
1868 KB |
Output is correct |
22 |
Correct |
2 ms |
1868 KB |
Output is correct |
23 |
Correct |
2 ms |
1880 KB |
Output is correct |
24 |
Correct |
2 ms |
1872 KB |
Output is correct |
25 |
Correct |
2 ms |
1868 KB |
Output is correct |
26 |
Correct |
3 ms |
1868 KB |
Output is correct |
27 |
Correct |
2 ms |
1868 KB |
Output is correct |
28 |
Correct |
2 ms |
1884 KB |
Output is correct |
29 |
Correct |
3 ms |
1884 KB |
Output is correct |
30 |
Correct |
3 ms |
1868 KB |
Output is correct |
31 |
Correct |
2 ms |
1996 KB |
Output is correct |
32 |
Correct |
2 ms |
1880 KB |
Output is correct |
33 |
Correct |
3 ms |
1884 KB |
Output is correct |
34 |
Correct |
4 ms |
1872 KB |
Output is correct |
35 |
Correct |
9 ms |
1872 KB |
Output is correct |
36 |
Correct |
10 ms |
1884 KB |
Output is correct |
37 |
Correct |
11 ms |
1884 KB |
Output is correct |
38 |
Correct |
3 ms |
1888 KB |
Output is correct |
39 |
Correct |
5 ms |
1888 KB |
Output is correct |
40 |
Correct |
5 ms |
1872 KB |
Output is correct |