谁有高效的实现大数相乘除的代码！！ 我写的太慢了 大家看看

[Dinelgua]

代码稍后贴出

[Dinelgua]

#include <iostream>
#include <iomanip>
#include <algorithm>
using namespace std;
#include   <stdio.h>   
#include   <math.h>   
typedef struct maxvalue //从低位开始以链表形式记录字符串表示的超大数
{
    unsigned char data;
    maxvalue* pNext;
    maxvalue* pPre;
    maxvalue* pTail;
    int iSize;
}BitofMaxValue,* MaxValue;
void AddNode(MaxValue& value,unsigned char nodeValue);
MaxValue add(MaxValue value1,MaxValue value2);MaxValue Del(MaxValue value1,MaxValue value2);
MaxValue multiply(MaxValue value1,MaxValue value2);
void changeStrToMax(char* pStr,MaxValue& value);
void print(MaxValue value);
void maxDelete(MaxValue value);

[Dinelgua]

void main(void)   
{   
    while(true)
    {
        //begin init
        flushall();
        char value1[1024];
        memset(value1,0,1024);
        printf("请输入第一个操作数：");
        scanf("%s",value1);

        flushall();
        char value2[1024];
        memset(value2,0,1024);
        printf("请输入第二个操作数：");
        scanf("%s",value2);

        flushall();
        char oper = 0;
        printf("请输入操作符：");
        scanf("%c",&oper);
        //end init

        MaxValue maxvalue1=NULL,maxvalue2=NULL, result=NULL;
        changeStrToMax(value1,maxvalue1);
        changeStrToMax(value2,maxvalue2);

        if ('+' == oper)
        {
            result = add(maxvalue1,maxvalue2);
        }
        else if('-' == oper)
        {
            result = Del(maxvalue1,maxvalue2);
        }
        else if ('*' == oper)
        {
            result = multiply(maxvalue1,maxvalue2);
        }
        print(result);

        printf("\n");

        maxDelete(maxvalue1);
        maxDelete(maxvalue2);
        maxDelete(result); 
    }

}   
//为链表增加一项
void AddNode(MaxValue & value,unsigned char nodeValue)
{
    if (NULL == value)
    {
        value = new BitofMaxValue;
        value->data = nodeValue;
        value->pNext = NULL;
        value->pPre  =NULL;
        value->pTail = value;
        value->iSize = 1;
    }
    else
    {
        value->pTail->pNext = new BitofMaxValue;
        value->pTail->pNext->data = nodeValue;//赋值
        value->pTail->pNext->pNext = NULL;
        value->pTail->pNext->pPre = value->pTail; 
        value->pTail = value->pTail->pNext;//结尾指针指向新增点

        value->iSize++;//value增加一位
    }

}
//加法处理
MaxValue add(MaxValue value1,MaxValue value2)
{
    MaxValue result = NULL;

    MaxValue p1Cur=value1,p2Cur=value2,pResult=result;
    bool bUp1 = false;
    while (NULL!= p1Cur && NULL != p2Cur)
    {
        char temp[5];memset(temp,0,5);
        unsigned int iTempResult = p1Cur->data-'0'+p2Cur->data-'0';
        if (bUp1)
        {
            iTempResult+=1;
        }
        if ( 9 < iTempResult )//说明有进位情况
        {
            bUp1 = true;
            itoa(iTempResult - 10,temp,10);
            AddNode(result,temp[0]);
        }
        else
        {
            bUp1 = false;
            itoa(iTempResult,temp,10);
            AddNode(result,temp[0]);
        }
        p1Cur = p1Cur->pNext;
        p2Cur = p2Cur->pNext;
    }

    if ( NULL!= p1Cur)
    {
        while (NULL != p1Cur)
        {
            if (bUp1)
            {
                AddNode(result,p1Cur->data+1);
                bUp1 = false;
            }
            else
            {
                AddNode(result,p1Cur->data);
            }
            p1Cur = p1Cur->pNext;

        }
    }

    if ( NULL!= p2Cur)
    {
        while (NULL != p2Cur)
        {
            if (bUp1)
            {
                AddNode(result,p2Cur->data+1);
                bUp1 = false;
            }
            else
            {
                AddNode(result,p2Cur->data);
            }
            p2Cur = p2Cur->pNext;

        }
    }
    if (NULL == p1Cur && NULL == p2Cur && bUp1)
    {
        AddNode(result,'1');
    }
    return result;
}

[Sou2012]

。。。。又来这个了，等高手出现

[Dinelgua]

//减法处理
MaxValue Del(MaxValue value1,MaxValue value2)
{
    MaxValue result = NULL;
    MaxValue pResult=result;

    //p1Cur指向较大值
    MaxValue p1Cur,p2Cur;
    if ( value1->iSize > value2->iSize )
    {
        p1Cur = value1;
        p2Cur = value2;
    }
    else if (value1->iSize < value2->iSize)
    {
        p1Cur = value2;
        p2Cur = value1;
    }
    else if ( value1->pTail->data > value2->pTail->data )
    {
        p1Cur = value1;
        p2Cur = value2;
    }
    else if ( value1->pTail->data < value2->pTail->data)
    {
        p1Cur = value2;
        p2Cur = value1;
    }
    else
    {
        p1Cur = value1;
        p2Cur = value2;
    }

    bool bDown1 = false;
    while (NULL!= p1Cur && NULL != p2Cur)
    {
        char temp[5];memset(temp,0,5);
        int iDown1 =0;
        if (bDown1)
        {
            iDown1 = 1;
        }
        else
        {
            iDown1 = 0;
        }

        unsigned int iTempResult=0;
        if ( p1Cur->data >= (p2Cur->data+iDown1) )
        {
            iTempResult = (p1Cur->data-'0') - (p2Cur->data-'0') - iDown1;
            bDown1 = false;
        }
        else
        {
            //判断是否可以借一位，目前应该不用判断，前面已经保证1为较大值 if(p1Cur->pNext->data>0 || NULL!= p1Cur->pNext->pNext)
            iTempResult = 10+(p1Cur->data-'0') - (p2Cur->data-'0') - iDown1;
            bDown1 = true;
        }

        itoa(iTempResult,temp,10);
        AddNode(result,temp[0]);

        p1Cur = p1Cur->pNext;
        p2Cur = p2Cur->pNext;
    }

    if ( NULL!= p1Cur)
    {
        while (NULL != p1Cur)
        {
            if (bDown1)
            {
                if (0 < p1Cur->data)
                {
                    AddNode(result,p1Cur->data-1);
                    bDown1=false;
                }
                else
                {
                    AddNode(result,9);
                    bDown1 = true;
                }
            }
            else
            {
                AddNode(result,p1Cur->data);
            }
            p1Cur = p1Cur->pNext;

        }
    }
    return result;
}

[九桔猫]

blog.csdn.net/akirya

此blog有大数乘法源码

[Dinelgua]

//乘法处理
MaxValue multiply(MaxValue value1,MaxValue value2)
{   
    //相乘用多个相加来解决
    MaxValue result,pTempResult;

    //构造一个值为1的maxvalue
    MaxValue pDel1 = new BitofMaxValue;
    pDel1->data = '1';
    pDel1->pNext = NULL;
    pDel1->iSize = 1;
    pDel1->pTail = pDel1;
    pDel1->pPre = NULL;

    MaxValue pAdd0 = new BitofMaxValue;
    pAdd0->data = '0';
    pAdd0->pNext = NULL;
    pAdd0->iSize = 1;
    pAdd0->pTail = pDel1;
    pAdd0->pPre = NULL;

    pTempResult = Del(value2,pDel1);
    result = add(value1,pAdd0);
    while (pTempResult->iSize >0)
    {
        if (pTempResult->iSize == 1)
        {
            if (NULL!= pTempResult)
            {
                if ('0'== pTempResult->data)
                {
                    break;
                }

            }
        }
        MaxValue pDelete = result;
        result = add(value1,result);
        maxDelete(pDelete);pDelete = NULL;

        pDelete = pTempResult;
        pTempResult = Del(pTempResult,pDel1);
        maxDelete(pDelete);pDelete = NULL;
    }
    return result;
}
void changeStrToMax(char* pStr,MaxValue& value)
{//例如 -123456 那么链表存储顺序为第一项6->5>4..>-
    int iLen = (int)strlen(pStr);
    for (int i = iLen-1;i >= 0; i--)
    {
        AddNode(value,pStr[i]);
    }
}
void print(MaxValue value)
{
    MaxValue pValue = value->pTail;
    while (NULL!=pValue)
    {
        printf("%c",pValue->data);
        pValue = pValue->pPre;
    }
    printf("\n");
}
void maxDelete(MaxValue value)
{
    BitofMaxValue * pTemp = value->pTail;
    while (true)
    {
        value->pTail = pTemp->pPre;
        if (value->pTail)
        {
            delete pTemp;
            pTemp = value->pTail;
        }
        else //最后一个元素
        {
            delete pTemp;
            break;
        }
    }
} 

[Dinelgua]

感谢VBSpine