C语言实现的高精度计算器

原理：
使用数组存储数据，用模拟手工计算的方法实现。
代码：

/**************************************************************** RigorCalc.h: .*****************************************************************/#ifndef AFX_RIGORCALC_H__FC9C727A_5204_4798_9686_0CC00C25729C__INCLUDED_#define AFX_RIGORCALC_H__FC9C727A_5204_4798_9686_0CC00C25729C__INCLUDED_#define INT_BIT_MAX 255#define FLOAT_BIT_MAX 255#ifndef CONST    #ifdef __cplusplus        #define CONST const    #else        #define CONST    #endif#endiftypedef struct tagWTNumber {    int intbits;                     /* 整数数位*/    int floatbits;                   /* 小数有效数位*/    char infinite;                   /* 无穷大*/    char sign;                       /* 符号*/    char intpart[INT_BIT_MAX];       /* 整数部分*/    char floatpart[FLOAT_BIT_MAX];   /* 小数部分*/} WTNumber;/* 算术函数指针类型.*/typedef void (*PFNCALC)(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes);/* 初始化WTNumber为0.*/void InitWTNumberToZero(WTNumber *pNum);/* 判断需要多少个字符空间存储WTNumber转换的字符串.*/int CharArrLenByWTNumber(CONST WTNumber* pNum);/* 从字符串转换到WTNumber.*/void CharArrToWTNumber(CONST char *arr,WTNumber *pNum);/* 从WTNumber转换到字符串.*/void WTNumberToCharArr(char *szBuf,CONST WTNumber *pNum);/* 调节数位,删除最高整数位是0的和最低小数位是0的数位.*/void AdjustBits(WTNumber *pNum);/* 移动小数点,deta=0不移动,deta<0往左移动,deta>0往右移动.*/void MoveFloatPoint(WTNumber *pNum,int deta);/* 使无穷大 */void MakeInfinite(WTNumber *pNum);/* 根据算术函数返回结果 */char *Result(CONST char *val1,CONST char *val2,PFNCALC pfnCalc);/* 比较2个数大小 */int WTCompare(CONST WTNumber* pn1,CONST WTNumber* pn2);/* 判断是否为0 */int IsZero(CONST WTNumber *pNum);/* 加法*/void WTAdd(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes);/* 乘法*/void WTMultiply(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes);/* 减法*/void WTSubtract(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes);/* 除法*/void WTDivide(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes);#endif /* AFX_RIGORCALC_H__FC9C727A_5204_4798_9686_0CC00C25729C__INCLUDED_ */

/************************************************* RigorCalc.c: implementation************************************************/#include <stdio.h>#include <stdlib.h>#include <string.h>#include "Rigor.h"void InitWTNumberToZero(WTNumber *pNum){    memset(pNum,0,sizeof(WTNumber));}void AdjustBits(WTNumber *pNum){    while(pNum->intbits>1&&pNum->intpart[pNum->intbits-1]==0) pNum->intbits--;    while(pNum->floatbits&&pNum->floatpart[pNum->floatbits-1]==0) pNum->floatbits--;}void MoveFloatPoint(WTNumber *pNum,int deta){    /* deta<0则往左移动小数点,deta>0则向右移动小数点 */    if(deta)    {        WTNumber n=*pNum;        InitWTNumberToZero(pNum);        pNum->sign=n.sign;        if(deta<0)        {            int i;            deta=-deta;            for(i=deta;i<n.intbits;i++)            {                pNum->intpart[pNum->intbits++]=n.intpart[i];            }            for(i=deta-1;i>=0;i--)            {                pNum->floatpart[pNum->floatbits++]=n.intpart[i];            }            for(i=0;i<n.floatbits;i++)            {                pNum->floatpart[pNum->floatbits++]=n.floatpart[i];            }        }        else        {            int i;            for(i=deta;i<n.floatbits;i++)   /* 处理小数部分*/            {                pNum->floatpart[pNum->floatbits++]=n.floatpart[i];            }            for(i=deta-1;i>=0;i--)  /* 小数到整数的部分*/            {                pNum->intpart[pNum->intbits++]=n.floatpart[i];            }            for(i=0;i<n.intbits;i++)    /* 整数部分*/            {                pNum->intpart[pNum->intbits++]=n.intpart[i];            }        }    }    AdjustBits(pNum);}int CharArrLenByWTNumber(CONST WTNumber* pNum){    int len = pNum->floatbits+pNum->intbits+1;    if(pNum->intbits==0) len++; /* .1 --> 0.1*/    if(pNum->floatbits) len++;  /* '.'*/    if(pNum->sign) len++;       /* '-'*/    if(pNum->infinite) return 11;    /* #INFINITE */    return len;}void CharArrToWTNumber(CONST char *arr,WTNumber *pNum){    char *point;    InitWTNumberToZero(pNum);    if(*arr=='-')   /* 如果是负数*/    {        arr++;        pNum->sign=1;    }    point=strchr(arr,'.');    if(point)   /* 找到小数点 */    {        int n=pNum->intbits=point-arr;  /* 计算出整数数位 */        while(n)    /* 整数数位不==0则循环 */        {            pNum->intpart[pNum->intbits-n]=arr[n-1]-'0';    /* 将数字低位存在低下标元素*/            n--;        }        while(*++point)        {            pNum->floatpart[pNum->floatbits]=*point-'0';            pNum->floatbits++;        }    }    else    /* 说明没写小数点,全是整数.*/    {        int n=pNum->intbits=strlen(arr);        while(n)        {            pNum->intpart[pNum->intbits-n]=arr[n-1]-'0';            n--;        }    }    AdjustBits(pNum);    /* 处理-0 和0的情况*/    if(pNum->floatbits==0)    {        if(pNum->intbits==0 || pNum->intbits==1&&pNum->intpart[0]==0)            pNum->sign=0;    }}void WTNumberToCharArr(char *szBuf,CONST WTNumber* pNum){    int n=pNum->intbits,c;    memset(szBuf,0,CharArrLenByWTNumber(pNum));    if(pNum->sign)  /* 如果是负数*/    {        *szBuf++='-';    }    if(pNum->infinite)     {        strcat(szBuf,"#INFINITE");        return;    }    while(n)    {        szBuf[pNum->intbits-n]=pNum->intpart[n-1]+'0';        n--;    }    c=0;    /* 是否加了0*/    if(pNum->intbits==0) {        strcat(szBuf,"0");        c=1;    }    if(pNum->floatbits) strcat(szBuf,".");    n=0;    while(n<pNum->floatbits)    {        szBuf[pNum->intbits+1+n+c]=pNum->floatpart[n]+'0';        n++;    }}char *Result(CONST char *val1,CONST char *val2,PFNCALC pfnCalc){    static char *s_szRes=NULL;    WTNumber n1,n2,res;    if(s_szRes) {        /*delete [] s_szRes;*/        free(s_szRes);        s_szRes=NULL;    }    CharArrToWTNumber(val1,&n1);    CharArrToWTNumber(val2,&n2);    pfnCalc(&n1,&n2,&res);/*  s_szRes = new char[CharArrLenByWTNumber(&res)];*/    s_szRes=(char*)malloc(CharArrLenByWTNumber(&res)*sizeof(char));    WTNumberToCharArr(s_szRes,&res);    return s_szRes;}int WTCompare(CONST WTNumber* pn1,CONST WTNumber* pn2){    /* 首先是比较符号*/    if(pn1->sign==0&&pn2->sign!=0)  /* pn1是正数,pn2是负数*/        return 1;   /* >*/    else if(pn1->sign!=0&&pn2->sign==0) /* pn1是负数,pn2是正数*/        return -1;  /* <*/    else    /* 同号状态*/    {        /* 比较整数部分*/        if(pn1->intbits>pn2->intbits)   /* pn1整数数位多*/            return pn1->sign?-1:1;        else if(pn1->intbits<pn2->intbits)            return pn1->sign?1:-1;        else    /* 整数数位相同*/        {            int i=pn1->intbits-1;   /*指到最高位*/            while(i>=0)            {                if(pn1->intpart[i]>pn2->intpart[i])                    return pn1->sign?-1:1;                else if(pn1->intpart[i]<pn2->intpart[i])                    return pn1->sign?1:-1;                else i--;            }            /* 整数部分相同,比较小数部分*/            for(i=0;i<pn1->floatbits&&i<pn2->floatbits;)            {                if(pn1->floatpart[i]>pn2->floatpart[i])                    return pn1->sign?-1:1;                else if(pn1->floatpart[i]<pn2->floatpart[i])                    return pn1->sign?1:-1;                else i++;            }            if(i<pn1->floatbits) return pn1->sign?-1:1;            if(i<pn2->floatbits) return pn1->sign?1:-1;            return 0;   /* 相等*/        }    }}void MakeInfinite(WTNumber *pNum){    pNum->infinite=1;}int IsZero(CONST WTNumber* pNum){    if(pNum->floatbits==0&&pNum->intbits==0) return 1;    if(pNum->floatbits==0&&pNum->intbits==1&&pNum->intpart[0]==0) return 1;    return 0;}void WTAdd(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes){    InitWTNumberToZero(pRes);    if(pn1->sign^pn2->sign) /*异号*/    {        WTNumber n2=*pn2;        n2.sign=pn1->sign;        WTSubtract(pn1,&n2,pRes);    }    else    /*同号*/    {        int maxfloatbits=pn1->floatbits>pn2->floatbits?pn1->floatbits:pn2->floatbits;        int addbit=0;   /* 进位值*/        int i,j;        for(i=maxfloatbits-1;i>=0;i--)        {            int value=pn1->floatpart[i]+pn2->floatpart[i]+addbit;            addbit=value/10;    /* 看看是否超过10. 设置进位值*/            pRes->floatpart[i]=value%10;        }        pRes->floatbits=maxfloatbits;        /* 到此,小数部分计算完毕.*/        for(j=0;j<pn1->intbits||j<pn2->intbits;j++)        {            int value=pn1->intpart[j]+pn2->intpart[j]+addbit;            addbit=value/10;            pRes->intpart[j]=value%10;            pRes->intbits++;        }        if(addbit>0)        {            pRes->intpart[j]=addbit;            pRes->intbits++;        }        pRes->sign=pn1->sign;   /*决定符号*/        AdjustBits(pRes);    }}void WTMultiply(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes){    WTNumber z1=*pn1,z2=*pn2;    WTNumber sum={0};    int i,j;    InitWTNumberToZero(pRes);    MoveFloatPoint(&z1,z1.floatbits);    MoveFloatPoint(&z2,z2.floatbits);    /* 计算z1*z2 */    for(i=0;i<z2.intbits;i++)    {        WTNumber tmp={0};   /* 存放临时乘积*/        int addbit=0;        tmp.intbits=z1.intbits+i;        for(j=0;j<z1.intbits;j++)        {            int value = z2.intpart[i]*z1.intpart[j]+addbit;            addbit=value/10;            tmp.intpart[j+i]=value%10;        }        if(addbit)        {            tmp.intpart[j+i]=addbit;            tmp.intbits++;        }        WTAdd(&sum,&tmp,pRes);        sum=*pRes;    }    *pRes=sum;    MoveFloatPoint(pRes,-(pn1->floatbits+pn2->floatbits));    /* 判断符号,异号为负*/    if(pn1->sign^pn2->sign) pRes->sign=1;}void WTSubtract(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes){    InitWTNumberToZero(pRes);    if(pn1->sign^pn2->sign) /* 异号情况*/    {        WTNumber n2=*pn2;        n2.sign=pn1->sign;        WTAdd(pn1,&n2,pRes);    }    else    /* 同号情况*/    {        int cmp=WTCompare(pn1,pn2);        int swapflag,i,maxfloatbits,subtractbit;        if(cmp==0) return;  /* 相等就没必要再减了.*/        swapflag=pn1->sign==0?cmp==-1:cmp==1;        if(swapflag)        {            CONST WTNumber* p=pn1;            pn1=pn2;            pn2=p;        }        maxfloatbits=pn1->floatbits>pn2->floatbits?pn1->floatbits:pn2->floatbits;        subtractbit=0;  /* 退位值*/        /* 先计算小数部分*/        for(i=maxfloatbits-1;i>=0;i--)        {            if(pn1->floatpart[i]-subtractbit<pn2->floatpart[i])            {                int value=pn1->floatpart[i]-pn2->floatpart[i]-subtractbit+10;                subtractbit=1;                pRes->floatpart[i]=value;            }            else            {                int value=pn1->floatpart[i]-pn2->floatpart[i]-subtractbit;                subtractbit=0;                pRes->floatpart[i]=value;            }        }        pRes->floatbits=maxfloatbits;        /* 至此小数部分计算完毕.*/        for(i=0;i<pn1->intbits||i<pn2->intbits;i++)        {            if(pn1->intpart[i]-subtractbit<pn2->intpart[i])            {                int value=pn1->intpart[i]-pn2->intpart[i]-subtractbit+10;                subtractbit=1;                pRes->intpart[i]=value;            }            else            {                int value=pn1->intpart[i]-pn2->intpart[i]-subtractbit;                subtractbit=0;                pRes->intpart[i]=value;            }            pRes->intbits++;        }        pRes->sign=swapflag?!pn1->sign:pn1->sign;   /*决定符号*/        AdjustBits(pRes);    }}void WTDivide(CONST WTNumber* pn1,CONST WTNumber* pn2,WTNumber* pRes){    WTNumber z1=*pn1,z2=*pn2;    int deta=z2.floatbits-z1.floatbits;    MoveFloatPoint(&z1,z1.floatbits);    MoveFloatPoint(&z2,z2.floatbits);    InitWTNumberToZero(pRes);    if(IsZero(pn1)) return ;    if(IsZero(pn2)) {        pRes->sign=pn1->sign;        MakeInfinite(pRes);        return ;    }    z1.sign=z2.sign=0;                /*统一符号,便于比较大小*/     while(z1.intbits!=z2.intbits) {    /*确保数位相等,这步耗费很多时间*/        if(z1.intbits<z2.intbits) {            MoveFloatPoint(&z1,1);            deta--;        } else {            MoveFloatPoint(&z2,1);            deta++;        }    }    while(pRes->floatbits<(INT_BIT_MAX/2)) {        int cmp=WTCompare(&z1,&z2);        int n=10;        WTNumber mulres={0},subres={0};        if(cmp==-1) {      /*z1<z2*/            MoveFloatPoint(&z1,1);            pRes->floatpart[pRes->floatbits++]=0;            continue;        } else if(cmp==0) { /*z1==z2*/            pRes->floatpart[pRes->floatbits++]=1;            break;        }        do {    /*找商*/            WTNumber tmp={0};            tmp.intpart[0]=--n;            tmp.intbits=1;            WTMultiply(&z2,&tmp,&mulres);        } while((cmp=WTCompare(&mulres,&z1))==1);        pRes->floatpart[pRes->floatbits++]=n;        if(cmp==0) break;        WTSubtract(&z1,&mulres,&subres);        MoveFloatPoint(&subres,1);        z1=subres;    }    MoveFloatPoint(pRes,1);    MoveFloatPoint(pRes,deta);    /* 判断符号,异号为负*/    if(pn1->sign^pn2->sign) pRes->sign=1;}

#include <stdio.h>#include "Rigor.h"typedef char CHARARR[256];int main(){    CHARARR num1;    CHARARR num2;    puts("Input two numbers,please:");    while(scanf("%s%s",num1,num2)!=-1) {        printf("The result of addition:\n%s\n",Result(num1,num2,WTAdd));        printf("The result of subtration:\n%s\n",Result(num1,num2,WTSubtract));        printf("The result of multiplication:\n%s\n",Result(num1,num2,WTMultiply));        printf("The result of divide:\n%s\n",Result(num1,num2,WTDivide));        puts("Input two numbers,please:");    }    return 0;}

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