BZOJ 4563 错排+高精度

//By SiriusRen
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
struct Bignum{
    int a[1024],num;
    void init(){memset(a,0,sizeof(a));num=0;}
    friend Bignum operator+(Bignum a,Bignum b){
        Bignum c;c.init();
        for(int i=1;i<=max(a.num,b.num);i++)
            c.a[i]=a.a[i]+b.a[i];
        for(int i=1;i<=a.num+b.num;i++){
            c.a[i+1]+=c.a[i]/10,c.a[i]%=10;
            if(c.a[i])c.num=i;
        }return c;
    }
    friend Bignum operator*(Bignum a,Bignum b){
        Bignum c;c.init();
        for(int i=1;i<=a.num;i++)
            for(int j=1;j<=b.num;j++)
                c.a[i+j-1]+=a.a[i]*b.a[j];
        for(int i=1;i<=a.num+b.num;i++){
            c.a[i+1]+=c.a[i]/10,c.a[i]%=10;
            if(c.a[i])c.num=i;
        }return c;
    }
}f[222],g;
int main(){
    int n;
    f[2].a[1]=f[2].num=g.num=1,g.a[1]=1;
    for(int i=3;i<=200;i++)g=g+f[2],f[i]=(f[i-1]+f[i-2])*g;
    scanf("%d",&n);
    for(int j=f[n].num;j;j--)printf("%d",f[n].a[j]);
}