FZU 2020

大整数取模，lucas 定理

#include <cstdio>#include <cstring>#include <iostream>using namespace std;#define LL __int64LL n,m,p;LL Quick_Mod(LL a,LL b,LL mod){    LL r = 1;    while(b){        if(b & 1) r = (r * a) % mod;        a = (a * a) % mod;        b >>= 1;    }    return r;}LL Cm(LL n,LL m,LL p){    LL a,b,r = 1;    for(LL i = 1;i <= m;i++){        a = (n + i - m) % p;        b = i % p;        r = r *(a * Quick_Mod(b,p - 2,p) % p) % p;    }    return r;}LL Lucas(LL n,LL m,LL p){    if(m == 0) return 1;    return (Lucas(n/p,m/p,p) * Cm(n % p,m % p,p)) % p;}int main(){    int T;    while(~scanf("%d",&T)){        while(T--){            scanf("%I64d%I64d%I64d",&n,&m,&p);            printf("%I64d\n",Lucas(n,m,p));        }    }    return 0;}