完全正负大数模板（正负数加减乘除求模运算）~~~~~

来源：互联网发布：百度一下软件编辑：程序博客网时间：2024/05/21 19:50

原模板是从kuangbin的acm模板里copy过来的，根据博主的代码风格对于模板做了一些写法上的小调整，不过呢~

因为博主本人有强迫症（ACMer通病）~~~所以经过一个下午+晚上的修改，将原来只支持无符号大整数的运算改成了支持有符号大整数的运算~~乘法除法挺好修改的，对于新的加法减法写了两个只支持无符号大数的加减法，根据运算符两边的符号位决定运算方式~~~顺便加上了大整数之间的除法运算和几个比较运算符~

模板检查了些许遍，应该没有啥bug了，除了输入-0(本来就不应该吗~)~~~~(有发现的童鞋一定要戳我~~~)

检验状况：

附上模板吧

//Copy from kuangbin~,modify by Siryuanshao#include <iostream>#include <algorithm>#include <iomanip>#include <cstdio>#include <cstring>#define MAXN 999999999#define MAXSIZE 5000#define DLEN 9using namespace std;class BigInt{    private:        int a[500];        int len;        bool sign;        //sign表示符号位的正负~    protected:        BigInt add(const BigInt&,const bool)const;        BigInt subtract(const BigInt&,const bool)const;         //两个无符号整形的加减法,flag标明结果的符号位~~    public:        BigInt() {sign=false;len=1;memset(a,0,sizeof(a));}        BigInt(const int);        BigInt(const char*);        BigInt(const BigInt&);        BigInt& operator=(const BigInt&);        friend istream& operator>>(istream&,BigInt&);        friend ostream& operator<<(ostream&,const BigInt&);        friend BigInt abs(const BigInt&);        BigInt operator+(const BigInt&)const;        BigInt operator-(const BigInt&)const;        BigInt operator*(const BigInt&)const;        BigInt operator/(const BigInt&)const;        BigInt operator/(const int&)const;        BigInt operator^(const int&)const;        int operator%(const int&)const;        bool operator<(const BigInt&)const;        bool operator>(const BigInt&)const;        bool operator<=(const BigInt&)const;        bool operator>=(const BigInt&)const;        bool operator==(const BigInt&)const;        inline int size() {return DLEN*(len-1)+to_string(a[len-1]).size();}};//对于负数的处理~~~BigInt::BigInt(const int b){    int c,d=abs(b);    len=0;    sign=b<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;}BigInt::BigInt(const char *in){    const char *s;    if(in[0]=='-') s=in+1,sign=true;    else s=in,sign=false;    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;    }}BigInt::BigInt(const BigInt& T):len(T.len),sign(T.sign){    memset(a,0,sizeof(a));    for(int i=0;i<len;i++)        a[i]=T.a[i];}BigInt& BigInt::operator=(const BigInt& n){    sign=n.sign;    len=n.len;    memset(a,0,sizeof(a));    for(int i=0;i<len;i++)        a[i]=n.a[i];    return *this;}//MDZZ~不是和字符串转化为BigInt一样么,233333istream& operator>>(istream& in,BigInt& b){    char ch[MAXSIZE];    in>>ch;    b=BigInt(ch);    return in;}ostream& operator<<(ostream& out,const BigInt& b){    out<<(b.sign?"-":"")<<b.a[b.len-1];    for(int i=b.len-2;i>=0;i--) out<<setw(DLEN)<<setfill('0')<<b.a[i];    return out;}BigInt abs(const BigInt& T){    BigInt t(T);    t.sign=false;    return t;}BigInt BigInt::add(const BigInt& T,const bool flag)const{    BigInt t(*this);    t.sign=flag;    int big;    big=T.len>len?T.len:len;    for(int 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;}BigInt BigInt::subtract(const BigInt& T,const bool flag)const{    BigInt t(*this);    t.sign=flag;    for(int i=0;i<t.len;i++)    {        if(t.a[i]<T.a[i])        {            //模拟借位运算过程~            int j=i+1;            while(t.a[j]==0) j++;            t.a[j--]--;            while(j>i) t.a[j--]+=MAXN;            t.a[i]+=MAXN+1-T.a[i];        }        else t.a[i]-=T.a[i];    }    while(t.a[t.len-1]==0&&t.len>1) t.len--;    return t;}BigInt BigInt::operator+(const BigInt& T)const{    BigInt ret;    if(sign^T.sign)    {        BigInt t1(*this),t2(T);        if(abs(t1)<abs(t2)) swap(t1,t2);        ret=t1.subtract(t2,t1.sign);        if(ret.a[ret.len-1]==0&&ret.len==1) ret.sign=false;    }    else ret=this->add(T,sign);    return ret;}BigInt BigInt::operator-(const BigInt& T)const{    BigInt ret;    if(sign^T.sign) ret=this->add(T,sign);    else    {        BigInt t1(*this),t2(T);        bool sn;        if(abs(t1)<abs(t2))        {            sn=t1.sign^1;            swap(t1,t2);        }        else sn=t1.sign;        ret=t1.subtract(t2,sn);        if(ret.a[ret.len-1]==0&&ret.len==1) ret.sign=false;    }    return ret;}BigInt BigInt::operator*(const BigInt& T)const{    BigInt ret;    long long up;    long long temp,temp1;    for(int i=0;i<len;i++)    {        up=0;        for(int j=0;j<T.len;j++)        {            temp=(long long)a[i]*T.a[j]+ret.a[i+j]+up;            if(temp>MAXN)            {                temp1=temp%(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+T.len]=up;    }    ret.sign=sign^T.sign;    ret.len=len+T.len;    while(ret.a[ret.len-1]==0&&ret.len>1) ret.len--;    return ret;}BigInt BigInt::operator/(const BigInt& T)const{    BigInt r(*this),ret(0);    while(r>=T)    {        BigInt down(1);        while(r-T*down>=0) down=down*10;        down=down/10;        r=r-T*down;        ret=ret+down;    }    ret.sign=sign^T.sign;    return ret;}BigInt BigInt::operator/(const int &b)const{    BigInt ret;    bool sign1=b<0;    long long down=0;    for(int i=len-1;i>=0;i--)    {        ret.a[i]=(a[i]+down*(MAXN+1))/b;        down=a[i]+down*(MAXN+1)-(long long)ret.a[i]*b;    }    ret.sign=sign^sign1;    ret.len=len;    while(ret.a[ret.len-1]==0&&ret.len>1) ret.len--;    return ret;}int BigInt::operator%(const int &b)const{    int d=0;    for(int i=len-1;i>=0;i--)        d=(((long long)d*(MAXN+1))%b+a[i])%b;    return sign?-d:d;}BigInt BigInt::operator^(const int &n)const{    BigInt ret(1),t(*this);    int m=n;    while(m)    {        if(m&1) ret=ret*t;        t=t*t;        m>>=1;    }    return ret;}bool BigInt::operator<(const BigInt& T)const{    if(sign&&!T.sign) return true;    if(!sign&&T.sign) return false;    //只有sign相同才能作比较~~    if(len!=T.len) return sign^(len<T.len);    for(int ln=len-1;ln>=0;ln--)        if(a[ln]!=T.a[ln]) return sign^(a[ln]<T.a[ln]);    return false;}bool BigInt::operator>(const BigInt& T)const{    return T<*this;}bool BigInt::operator<=(const BigInt& T)const{    if(*this==T) return true;    return *this<T;}bool BigInt::operator>=(const BigInt& T)const{    return T<=*this;}bool BigInt::operator==(const BigInt& T)const{    if(sign!=T.sign||len!=T.len) return false;    for(int i=len-1;i>=0;i--)        if(a[i]!=T.a[i]) return false;    return true;}

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