Lucas模板

#include <bits/stdc++.h>

using namespace std;

#define REP(i,n)        for(int i(0); i <  (n); ++i)
#define rep(i,a,b)        for(int i(a); i <= (b); ++i)
#define dec(i,a,b)        for(int i(a); i >= (b); --i)
#define for_edge(i,x)        for(int i = H[x]; i; i = X[i])

const int N    =    1000000        +    10;
const int M    =    10000        +    10;
const int Q    =    1000        +    10;
const int A    =    30        +    1;

typedef long long LL;


LL fac[N];

LL n, m, mod;

inline LL Pow(LL a, LL b, int Mod){ LL ret(1); for (; b; b >>= 1, (a *= a) %= Mod) if (b & 1) (ret *= a) %= Mod; return ret;}    

inline LL C(LL n, LL m){ return m > n ? 0 : fac[n] * Pow(fac[m] * fac[n - m] % mod, mod - 2, mod) % mod; }


LL Lucas(LL n, LL m){ return m == 0 ? 1 : (C(n % mod, m % mod) % mod) * (Lucas(n / mod, m / mod) % mod) % mod;  }

int main(){

    scanf("%lld %lld %lld", &n, &m, &mod);
    fac[0] = 1; rep(i, 1, N - 5) fac[i] = (fac[i - 1] * i) % mod;
    printf("%lld\n", Lucas(n, m));
    
    return 0;
    
}

来自cxhscst2，(～￣▽￣)～