bzoj1951【CRT】【Lucas】

忘了討論g=P的情況了qaq

然後加上以後又忘了寫return 0了qaq

所以愉快地wa了幾發

#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<cstring>
using namespace std;
typedef long long LL;
inline int read()
{
	int x=0;bool f=0;char c=getchar();
	for (;c<'0'||c>'9';c=getchar()) f=c=='-'?1:0;
	for (;c>='0'&&c<='9';c=getchar()) x=x*10+c-'0';
	return f?-x:x;
}
const int P[4]={2,3,4679,35617},mod=999911659;
LL n,g,ans=0,x[4],fac[40010],fc=0,p,ftc[40010];

inline void add(LL &a,LL b)
{
	a+=b;
	if (a>=p) a-=p;
}

inline LL qpw(LL a,LL k,LL p)
{
	LL rec=1;
	while (k)
	{
		if (k&1) rec=(rec*a)%p;
		a=(a*a)%p;k>>=1;
	}
	return rec;
}

LL cal_c(LL a,LL b)
{
	if (a<b) return 0;
	if (a<p&&b<p) return ftc[a]*qpw(ftc[b],p-2,p)%p*qpw(ftc[a-b],p-2,p)%p;
	return cal_c(a%p,b%p)*cal_c(a/p,b/p)%p;
}

LL cal()
{
	ftc[0]=1;
	for (int i=1;i<p;i++) ftc[i]=ftc[i-1]*i%p;
	LL rec=0;
	for (int i=1;i<=fc;i++) add(rec,cal_c(n,fac[i]));
	return rec;
}

int main()
{
	n=read();g=read();
	if (g==mod) return puts("0"),0;
	for (LL i=1;i*i<=n;i++) if (n%i==0)
	{
		fac[++fc]=i;
		if (i*i!=n) fac[++fc]=n/i;
	}
	sort(fac+1,fac+fc+1);
	for (int i=0;i<4;i++) p=P[i],x[i]=cal();
	p=mod-1;
	for (int i=0;i<4;i++)
	{
		LL k=(mod-1)/P[i];
		k=k*qpw(k,P[i]-2,P[i]);
		add(ans,k*x[i]%p);
	}
	ans=qpw(g,ans,mod);
	printf("%lld\n",ans);
	return 0;
}