UVA 10494 If We Were a Child Again（大数）

?

Input is a sequence of lines. Each line will contain an input number. One or more spaces. A sign (division or mod). Again spaces. And another input number. Both the input numbers are non-negative integer. The first one may be arbitrarily long. The second number?n?will be in the range (0 < n < 2³¹).

110 / 100

99 % 10

2147483647 / 2147483647

2147483646 % 2147483647

1

9

1

2147483646

代码：

    #include<iostream>
    #include<string>
    #include<iomanip>
    #include<algorithm>
    #include<string.h>
    #include<stdio.h>
    using namespace std;

    #define MAXN 9999
    #define MAXSIZE 300
    #define DLEN 4

    class BigNum
    {
    private:
        long long  a[500];    //可以控制大数的位数
        long long  len;       //大数长度
    public:
        BigNum(){ len = 1;memset(a,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 istream& operator>>(istream&,BigNum&);   //重载输入运算符
        friend ostream& operator<<(ostream&,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

        BigNum operator^(const int  &) const;    //大数的n次方运算
        long long     operator%(const int  &) const;    //大数对一个int类型的变量进行取模运算
        bool   operator>(const BigNum & T)const;   //大数和另一个大数的大小比较
        bool   operator>(const int & t)const;      //大数和一个int类型的变量的大小比较

        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
    {
        long long c,d = b;
        len = 0;
        memset(a,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
    {
        long long t,k,index,l,i;
        memset(a,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
    {
        long long i;
        memset(a,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
    {
        long  i;
        len = n.len;
        memset(a,sizeof(a));
        for(i = 0 ; i < len ; i++)
            a[i] = n.a[i];
        return *this;
    }
    istream& operator>>(istream & in,BigNum & b)   //重载输入运算符
    {
        char ch[MAXSIZE*4];
        long long i = -1;
        in>>ch;
        long long  l=strlen(ch);
        long long count=0,sum=0;
        for(i=l-1;i>=0;)
        {
            sum = 0;
            long long 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++;
        return in;

    }
    ostream& operator<<(ostream& out,BigNum& b)   //重载输出运算符
    {
        long long i;
        cout << b.a[b.len - 1];
        for(i = b.len - 2 ; i >= 0 ; i--)
        {
            cout.width(DLEN);
            cout.fill('0');
            cout << b.a[i];
        }
        return out;
    }

    BigNum BigNum::operator+(const BigNum & T) const   //两个大数之间的相加运算
    {
        BigNum t(*this);
        long long 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
    {
        long long 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[t1.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;
        long long  i,up;
        long long 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;
        long long 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;
    }
    long long BigNum::operator %(const int & b) const    //大数对一个int类型的变量进行取模运算
    {
        long long  i,d=0;
        for (i = len-1; i>=0; i--)
        {
            d = ((d * (MAXN+1))% b + a[i])% b;
        }
        return d;
    }
    BigNum BigNum::operator^(const int & n) const    //大数的n次方运算
    {
        BigNum t,ret(1);
        long long i;
        if(n<0)
            exit(-1);
        if(n==0)
            return 1;
        if(n==1)
            return *this;
        long long m=n;
        while(m>1)
        {
            t=*this;
            for( i=1;i<<1<=m;i<<=1)
            {
                t=t*t;
            }
            m-=i;
            ret=ret*t;
            if(m==1)
                ret=ret*(*this);
        }
        return ret;
    }
    bool BigNum::operator>(const BigNum & T) const   //大数和另一个大数的大小比较
    {
        long long  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;
    }
    bool BigNum::operator >(const int & t) const    //大数和一个int类型的变量的大小比较
    {
        BigNum b(t);
        return *this>b;
    }

    void BigNum::print()    //输出大数
    {
        long long i;
        cout << a[len - 1];
        for(i = len - 2 ; i >= 0 ; i--)
        {
            cout.width(DLEN);
            cout.fill('0');
            cout << a[i];
        }
       // printf("*");
        cout << endl;
    }
    int main(void)
    {
        long long i,n,a;
        char s[10];
        BigNum x,y,z;      //定义大数的对象数组
        while(cin>>x)
        {
           scanf("%s",s);
           cin>>a;
           if(s[0]=='/'){
            z=x/a;
           }
           if(s[0]=='%'){
            z=x%a;
           }
            z.print();
        }
    }