2014 ACM/ICPC Asia Regional Shanghai Online 1006 Sawtooth

<pre name="code" class="cpp">#include<iostream>   
#include<string>   
#include<iomanip>   
#include<algorithm>   
#include<cstring>
#include<cstdio>
using namespace std;   
  
#define MAXN 9999  
#define MAXSIZE 10  
#define DLEN 4  
  
class BigNum  
{   
private:   
    int a[500];    //可以控制大数的位数   
    int len;       //大数长度  
public:   
    BigNum(){ len = 1;memset(a,0,sizeof(a)); }   //构造函数  
    BigNum(const int);       //将一个int类型的变量转化为大数  
    BigNum(const char*);     //将一个字符串类型的变量转化为大数  
    BigNum(const BigNum &);  //拷贝构造函数  
    BigNum &operator=(const BigNum &);   //重载赋值运算符，大数之间进行赋值运算  
  
    friend void cinn(BigNum&);   //重载输入运算符  
    friend void coutt(BigNum&);   //重载输出运算符  
  
    BigNum operator+(const BigNum &) const;   //重载加法运算符，两个大数之间的相加运算   
    BigNum operator-(const BigNum &) const;   //重载减法运算符，两个大数之间的相减运算   
    BigNum operator*(const BigNum &) const;   //重载乘法运算符，两个大数之间的相乘运算 
    BigNum operator/(const int   &) const;    //重载除法运算符，大数对一个整数进行相除运算  
    bool   operator>(const BigNum & T)const;   //大数和另一个大数的大小比较  
  
    void print();       //输出大数  
};   
BigNum::BigNum(const int b)     //将一个int类型的变量转化为大数  
{   
    int c,d = b;  
    len = 0;  
    memset(a,0,sizeof(a));  
    while(d > MAXN)  
    {  
        c = d - (d / (MAXN + 1)) * (MAXN + 1);   
        d = d / (MAXN + 1);  
        a[len++] = c;  
    }  
    a[len++] = d;  
}  
BigNum::BigNum(const char*s)     //将一个字符串类型的变量转化为大数  
{  
    int t,k,index,l,i;  
    memset(a,0,sizeof(a));  
    l=strlen(s);     
    len=l/DLEN;  
    if(l%DLEN)  
        len++;  
    index=0;  
    for(i=l-1;i>=0;i-=DLEN)  
    {  
        t=0;  
        k=i-DLEN+1;  
        if(k<0)  
            k=0;  
        for(int j=k;j<=i;j++)  
            t=t*10+s[j]-'0';  
        a[index++]=t;  
    }  
}  
BigNum::BigNum(const BigNum & T) : len(T.len)  //拷贝构造函数  
{   
    int i;   
    memset(a,0,sizeof(a));   
    for(i = 0 ; i < len ; i++)  
        a[i] = T.a[i];   
}   
BigNum & BigNum::operator=(const BigNum & n)   //重载赋值运算符，大数之间进行赋值运算  
{  
    int i;  
    len = n.len;  
    memset(a,0,sizeof(a));   
    for(i = 0 ; i < len ; i++)   
        a[i] = n.a[i];   
    return *this;   
}  
void cinn(BigNum & b)   //重载输入运算符  
{  
    char ch[MAXSIZE*4];  
    int i = -1;  
    scanf("%s",ch);  
    int l=strlen(ch);  
    int count=0,sum=0;  
    for(i=l-1;i>=0;)  
    {  
        sum = 0;  
        int t=1;  
        for(int j=0;j<4&&i>=0;j++,i--,t*=10)  
        {  
            sum+=(ch[i]-'0')*t;  
        }  
        b.a[count]=sum;  
        count++;  
    }  
    b.len =count++;  
  
}  
void coutt(BigNum& b)   //重载输出运算符  
{  
    int i;    
    printf("%d",b.a[b.len - 1]) ;   
    for(i = b.len - 2 ; i >= 0 ; i--)  
    {   
    printf("%04d",b.a[i]) ;   
    }   
}  
  
BigNum BigNum::operator+(const BigNum & T) const   //两个大数之间的相加运算  
{  
    BigNum t(*this);  
    int i,big;      //位数     
    big = T.len > len ? T.len : len;   
    for(i = 0 ; i < big ; i++)   
    {   
        t.a[i] +=T.a[i];   
        if(t.a[i] > MAXN)   
        {   
            t.a[i + 1]++;   
            t.a[i] -=MAXN+1;   
        }   
    }   
    if(t.a[big] != 0)  
        t.len = big + 1;   
    else  
        t.len = big;     
    return t;  
}  
BigNum BigNum::operator-(const BigNum & T) const   //两个大数之间的相减运算   
{    
    int i,j,big;  
    bool flag;  
    BigNum t1,t2;  
    if(*this>T)  
    {  
        t1=*this;  
        t2=T;  
        flag=0;  
    }  
    else  
    {  
        t1=T;  
        t2=*this;  
        flag=1;  
    }  
    big=t1.len;  
    for(i = 0 ; i < big ; i++)  
    {  
        if(t1.a[i] < t2.a[i])  
        {   
            j = i + 1;   
            while(t1.a[j] == 0)  
                j++;   
            t1.a[j--]--;   
            while(j > i)  
                t1.a[j--] += MAXN;  
            t1.a[i] += MAXN + 1 - t2.a[i];   
        }   
        else  
            t1.a[i] -= t2.a[i];  
    }  
    t1.len = big;  
    while(t1.a[len - 1] == 0 && t1.len > 1)  
    {  
        t1.len--;   
        big--;  
    }  
    if(flag)  
        t1.a[big-1]=0-t1.a[big-1];  
    return t1;   
}   
  
BigNum BigNum::operator*(const BigNum & T) const   //两个大数之间的相乘运算   
{   
    BigNum ret;   
    int i,j,up;   
    int temp,temp1;     
    for(i = 0 ; i < len ; i++)  
    {   
        up = 0;   
        for(j = 0 ; j < T.len ; j++)  
        {   
            temp = a[i] * T.a[j] + ret.a[i + j] + up;   
            if(temp > MAXN)  
            {   
                temp1 = temp - temp / (MAXN + 1) * (MAXN + 1);   
                up = temp / (MAXN + 1);   
                ret.a[i + j] = temp1;   
            }   
            else  
            {   
                up = 0;   
                ret.a[i + j] = temp;   
            }   
        }   
        if(up != 0)   
            ret.a[i + j] = up;   
    }   
    ret.len = i + j;   
    while(ret.a[ret.len - 1] == 0 && ret.len > 1)  
        ret.len--;   
    return ret;   
}     
BigNum BigNum::operator/(const int & b) const   //大数对一个整数进行相除运算  
{   
    BigNum ret;   
    int i,down = 0;     
    for(i = len - 1 ; i >= 0 ; i--)  
    {   
        ret.a[i] = (a[i] + down * (MAXN + 1)) / b;   
        down = a[i] + down * (MAXN + 1) - ret.a[i] * b;   
    }   
    ret.len = len;   
    while(ret.a[ret.len - 1] == 0 && ret.len > 1)  
        ret.len--;   
    return ret;   
}  
bool BigNum::operator>(const BigNum & T) const   //大数和另一个大数的大小比较  
{   
    int ln;   
    if(len > T.len)  
        return true;   
    else if(len == T.len)  
    {   
        ln = len - 1;   
        while(a[ln] == T.a[ln] && ln >= 0)  
            ln--;   
        if(ln >= 0 && a[ln] > T.a[ln])  
            return true;   
        else  
            return false;   
    }   
    else  
        return false;   
}

int main()
{
	int t,i;
	BigNum n;
	BigNum tmp=1,t1=8,t2=7;
	cin>>t;
	for(i=0;i<t;i++)
	{
		cinn(n);
		printf("Case #%d: ",i+1);
		if(tmp>n) cout<<1<<endl;
		else
		{
			n=t1*n*n-t2*n+1;
			coutt(n);
			printf("\n");
		}
	}
	return 0;
}