BZOJ 4591 超能粒子炮·改

按位推下式子就行了。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define maxn 2505
#define mod 2333
using namespace std;
long long t,n,k,c[maxn][maxn],s[maxn][maxn],to[maxn],ret=0,bitn[maxn],bitk[maxn];
void get_table()
{
    c[0][0]=1;for (long long i=0;i<mod;i++) s[0][i]=1;
    for (long long i=1;i<mod;i++)
    {
        c[i][0]=s[i][0]=1;
        for (long long j=1;j<mod;j++)
        {
            c[i][j]=(c[i-1][j]+c[i-1][j-1])%mod;
            s[i][j]=(s[i][j-1]+c[i][j])%mod;
        }
    }
    to[0]=1;
    for (long long i=1;i<mod;i++) to[i]=to[i-1]*2%mod;
}
void get_bit(long long n,long long k)
{
    ret=0;
    while (n) {bitn[++ret]=n%mod;n/=mod;}
    for (long long i=1;i<=ret;i++) {bitk[i]=k%mod;k/=mod;}
}
long long f_pow(long long x,long long y)
{
    long long base=x,ans=1;
    while (y)
    {
        if (y&1) ans=(ans*base)%mod;
        base=(base*base)%mod;
        y>>=1;
    }
    return ans;
}
long long inv(long long x) {return f_pow(x,2331);}
long long lucas_s(long long pos,long long r)
{
    if (!pos) return 1;
    long long ans1=s[bitn[pos]][bitk[pos]-1]*r%mod,ans2=c[bitn[pos]][bitk[pos]]*lucas_s(pos-1,r*inv(to[bitn[pos-1]])%mod)%mod;
    return (ans1+ans2)%mod;
}
int main()
{
    scanf("%lld",&t);get_table();
    for (long long i=1;i<=t;i++)
    {
        scanf("%lld%lld",&n,&k);
        get_bit(n,k);
        long long base=1;
        for (long long i=ret-1;i>=1;i--) base=(base*to[bitn[i]])%mod;
        printf("%lld\n",lucas_s(ret,base)%mod);
    }
    return 0;
}