大數模板——來自jxy師兄

#include <iostream>#include <cstring>#include <cstdio>#define MAX 1300#define base 10000#define baselen 4using namespace std;//int countnub = 0;//此大整數類用數組 digital[MAX]表示一個大整數;//一個 digital表示最大為 9999;//len 表示目前整數的用到最大digital位,sign表示符號;class Int{public :    //建構函式;    Int();    //比較函數,第二個參數為 0則表示絕對值比較;    int cmp(Int  ,int);    //判斷是否為0;    bool zero();    //判定奇偶性;    bool odd();    //右移一個二進位位    Int move();    //賦值;    Int operator = (int);    Int operator = (Int );    Int operator = (char*);    //雙目運算;    Int operator +(Int );    Int operator -(Int );    Int operator *(Int );    Int operator /(Int );    Int operator %(Int );    //輸入輸出;    friend ostream& operator <<(ostream&,Int );    friend istream& operator >>(istream& ,Int& );private :    int digital[MAX];    int sign;    int len;    //十進位移位    Int shift(int k);};Int ::Int(){    digital[len=0] = 0, sign = 1;}int Int::cmp(Int obj, int sel = 1)//sel若初始為0是絕對值比較{    if(sel&&obj.sign+sign == 0)return sign - obj.sign;  //比較加號或減號;    int k = len - obj.len;//比較長度;    if(k)return sel? sign*k : k;    for(k = len; k>0 && obj.digital[k] == digital[k]; k--);  //比較數位;    return sel? sign * ( digital[k] - obj.digital[k] ): digital[k]-obj.digital[k];}bool  Int::zero(){    return digital[0]+len ==0;}bool  Int:: odd(){    return digital[0]&1;}Int  Int::move(){    if(digital[0]<=1&&len==0)digital[0] = 0;    else    {        int k = len , t, carry=0;        if (digital[len]==1)len--;        while(k>=0)        {            t = digital[k]&1;            digital[k]= digital[k]>>1;            if(carry)digital[k] += base/2;            k--;            carry = t;        }    }    if(this->zero())sign = 1;    return *this;}///////////////////////////////////////////////////////////////////////////////////Int Int::operator =(Int obj){    for(len = 0, sign = obj.sign; len <= obj.len; len++)digital[len]=obj.digital[len];    len--;    return *this;}Int Int::operator = (int obj){    if(obj<0)sign = -1, obj = -obj;    else sign = 1;    digital[0] = obj%base;    if(obj/=base)    {        digital[1] = obj%base, len = 1;        if(obj/=base)digital[2] = obj%base, len = 2;    }    else len = 0;    return *this;}Int Int::operator =  (char *s){    int i, j, l, k;    if(s[0] == '-')l = 1,sign = -1;    else l = 0, sign = 1;    i=l;    while(s[i])i++;    i--;    k=0;    while(i-baselen+1>=l)    {        for(j=1,digital[k]=0; j<=baselen; j++)            digital[k]=digital[k]*10+s[i-baselen+j]-'0';        i = i-baselen,k++;    }    digital[k] = 0;    while(i>=l)digital[k] = digital[k]*10 + s[l++] - '0';    if(k)len = k-(digital[k]==0);    else len = 0;    return *this;}/////////////////////////////////////////////////////////////////Int Int::operator +(Int obj){    Int sum;    if(obj.sign==sign)   //同號加;    {        int carry;        int i;        for(i = carry = 0; i <= len && i <= obj.len; i++)            carry  =  carry  + digital[i]  + obj.digital[i],  sum.digital[i]    =  carry%base,                      carry = carry/base;        for(; i <= len; i++)            carry  =  carry  +  digital[i],  sum.digital[i]    =  carry%base,  carry  =                          carry/base;        for(; i <= obj.len; i++)            carry  =  carry  +obj.digital[i],  sum.digital[i]    =  carry%base,  carry  =                          carry/base;        sum.len = i-!(sum.digital[i] = carry);        sum.sign = sign;        return sum;    }    else    //異號變同號減法;    {        sum = obj;        sum.sign = -sum.sign;        return *this-sum;    }}Int  Int::operator -(Int obj){    Int *sub1, *sub2, quotient;    if(sign==obj.sign)   //同號減;    {        int i, carry;        i = this->cmp(obj,0);//絕對值比較;        if(i==0)return quotient;        else if(i<0)sub1 = &obj, sub2 = this, quotient.sign = -sign;        else sub1 = this, sub2 = &obj, quotient.sign = sign;        for(i = carry = 0; i <= sub2->len; i++)            if(  (quotient.digital[i] = sub1 ->digital[i] - carry - sub2->digital[i]) < 0)                carry = 1, quotient.digital[i] += base;//借位;            else carry = 0;        for(; i <= sub1->len; i++)            if(  (quotient.digital[i]  =  sub1  ->digital[i]  -  carry  )<  0  )carry  =  1,                        quotient.digital[i] += base;//借位;            else carry = 0;        i--;        while(i&"ient.digital[i]==0)i--;        quotient.len = i;        return quotient;    }    else      //異號變同號加:    {        quotient = obj, quotient.sign = -obj.sign;        return *this + quotient;    }}Int Int::operator *(Int obj){    int carry, i, j, maxlen;    Int product;    maxlen = obj.len + len + 2;    memset( product.digital, 0, sizeof(int)*maxlen );    for(i = 0; i <= obj.len; i++)    {        for(j =0, carry = 0; j <= len; j++)        {            carry += obj.digital[i] * digital[j] +product.digital[j+i];            product.digital[j+i] = carry%base;            carry/=base;        }        while(carry) product.digital[i+j++] = carry%base, carry /= base;    }    i = maxlen-1;    while(i&&product.digital[i]==0)i--;    product.len = i;    if(product.zero())product.sign = 1;//確定符號    else product.sign = sign*obj.sign;    return product;}Int Int::operator /( Int obj){    int div,    k,   flag;    Int x, y, z;    x = *this;    flag = obj.sign*sign;    obj.sign = x.sign = 1;    while( x.cmp(obj) >0 )    {        k = x.len-obj.len;        if(  x.digital[x.len]  >  obj.digital[obj.len]  )  div  =                x.digital[x.len]/(obj.digital[obj.len]+1);        else  if(x.len>obj.len)k--,  div  =                (x.digital[x.len]*base+x.digital[x.len-1])/(obj.digital[obj.len]+1);        else break;        x = x - ( obj*(z=div) ).shift(k);        y = y+ z.shift(k);    }    if(x.cmp(obj)>=0)y = y+(z=1);    if(y.zero())y.sign=1;    else y.sign=flag;    return y;}Int Int::operator %(Int obj){    int div,   k;    Int x, y, z;    x = *this;    obj.sign = x.sign = 1;    while( x.cmp(obj) >0 )    {        k = x.len-obj.len;        if(  x.digital[x.len]  >  obj.digital[obj.len]  )  div  =                x.digital[x.len]/(obj.digital[obj.len]+1);        else  if(x.len>obj.len)k--,  div  =                (x.digital[x.len]*base+x.digital[x.len-1])/(obj.digital[obj.len]+1);        else break;        x = x - ( obj*(z=div) ).shift(k);    }    if(x.cmp(obj)>=0)x = x-obj;    if(x.zero())x.sign = 1;    else x.sign = sign;    return x;}Int Int::shift(int k){    Int temp;    int i;    temp = *this;    for(i=0; i<=len; i++)temp.digital[i+k]=digital[i];    for(i=0; i<k; i++)temp.digital[i] = 0;    temp.sign = sign;    temp.len = len+k;    return temp;}///////////////////////////////////////////////////////////////////////ostream& operator <<(ostream& out,Int obj ){    int i = obj.len;    if(obj.sign==-1)out<<'-';    out<<obj.digital[i--];    out.fill('0');    out.setf(ios::right);    while(i>=0)    {        out.width(baselen);        out<<obj.digital[i--];    }    return out;}istream& operator >>(istream& in,Int& obj){    char s[baselen*MAX];    in>>s;    obj = s;    return in;}int main(){    Int a, b;    while(cin >> a >> b)    {        cout << a+b << endl;        cout << a-b << endl;        cout << a*b << endl;        cout << a/b << endl;    }    return 0;}