看起来超级简单的题，除了那2005位数。。。正好这几天都在做高精度乘法和加法的题，自己写了一个类。

    下面是我的AC代码：直接加的话内存会爆，所以我又特地写了一个函数，呵呵。。。7038的原因是strlen(t[7037])==2005.

#include 
     
      using namespace std;const int MAX_LEN=2010;int temp[MAX_LEN];class bigNumber{public:    bigNumber()    {        memset(number,0,sizeof(number));        number[0]='0';    }    bigNumber(char *str)    {        memcpy(number,str,strlen(str)+1);    }    bigNumber(int a)    {        int i=0;        memset(number,0,sizeof(number));        if(a==0)            number[0]='0';        else        {            while(a)            {                number[i++]=a%10+'0';                a/=10;            }            _strrev(number);        }    }    ~bigNumber()    {    }    char* getNumber()    {        return number;    }    friend ostream& operator<<(ostream& output, bigNumber& t)    {        output<
      
       getNumber())>strlen(t.getNumber())?this:&t;        bigNumber* b=strlen(this->getNumber())>strlen(t.getNumber())?&t:this;        bigNumber* c=new bigNumber();        char *x=a->getNumber();        char *y=b->getNumber();        char *z=c->getNumber();        int lenx=strlen(x);        int leny=strlen(y);        int i;        int flag=0;        for(i=0;i
       
        9;            z[i]=z[i]%10+'0';        }        for(;i
        
         9;            z[i]=z[i]%10+'0';        }        if(flag)            z[i]='1';        _strrev(z);        return *c;    }    void addFourNumber(bigNumber& a,bigNumber& b,bigNumber& c,bigNumber& d)    {        int i,len,lenx,leny,lenp,lenq;        int flag=0;        char *x=a.getNumber();        char *y=b.getNumber();        char *p=c.getNumber();        char *q=d.getNumber();        char *z=this->getNumber();                lenx=strlen(x);        leny=strlen(y);        lenp=strlen(p);        lenq=strlen(q);        len=lenx>leny?lenx:leny;        len=lenp>len?lenp:len;        len=lenq>len?lenq:len;        for(i=0;i
         
          getNumber();        char *y=t.getNumber();        char *z=c->getNumber();        int lenx=strlen(x);        int leny=strlen(y);        int i,j;        memset(temp,0,sizeof(temp));        for(i=0;i
          
           9;i++) { if(temp[i]>9) temp[i+1]+=temp[i]/10; z[i]=temp[i]%10+'0'; } z[i]=temp[i]+'0'; while(z[i]=='0') z[i--]=0; _strrev(z); return *c; } bigNumber& operator=(bigNumber& t) { memcpy(number,t.getNumber(),strlen(t.getNumber())+1); return *this; } bigNumber& operator=(char *str) { memcpy(number,str,strlen(str)+1); return *this; }private: char number[MAX_LEN];};bigNumber t[7038]={ 1,1,1,1,1};int main(){ int i; for(i=5;i<7038;i++) t[i].addFourNumber(t[i-1],t[i-2],t[i-3],t[i-4]); while(cin>>i) cout<
           
            <