c語言-C語言中，我想依次讀入兩個非常大的數，用字符串存，

C語言中，我想依次讀入兩個非常大的數，用字符串存，

C語言中，我想依次讀入兩個非常大的整數，用字符串存，應該怎麼寫讀入語句，並且想計算他們的和，並輸出結果，應該怎麼辦（這兩個整數非常大，long int也不能存）

最佳回答：

/**********  main function *********/

/*
** FILE:     tbigint.c
** NOTE:     2015-10-08 created by Jack Liu
*/
#include<stdio.h>
#include<string.h>
#include"bigint.h"

int
main( void )
{
        char caOper1[ 100 ] = { 0 };
        char caOper2[ 100 ] = { 0 };
        st_bigint stOper1;
        st_bigint stOper2;
        st_bigint stResult;

        stOper1.iFlag = POSITIVE;
        stOper1.iUsed = 0;
        memset( stOper1.iaValue, 0x00, sizeof( stOper1.iaValue ) );

        memcpy( &stOper2, &stOper1, sizeof( st_bigint ) );
        memcpy( &stResult, &stOper1, sizeof( st_bigint ) );

        printf( "input operand 1: " );
        scanf( "%s", caOper1 );
        printf( "input operand 2: " );
        scanf( "%s", caOper2 );

        str2bigint( caOper1, &stOper1 );
        str2bigint( caOper2, &stOper2 );

        printf( "first operand : " );
        print_bigint( &stOper1 );
        printf( "\n" );
        printf( "second operand: " );
        print_bigint( &stOper2 );
        printf( "\n" );


        add_bigint( &stOper1, &stOper2, &stResult );
        printf( "result output : " );
        print_bigint( &stResult );
        printf( "\n" );

        return 0;
}

/************************************/
/************** detail **************/
/***********************************/
/*
** FILE:    bigint.h
** NOTE:    2015-10-08 created by Jack Liu
*/
#ifndef JACK_LIU_COM_BIGINT_H
#define JACK_LIU_COM_BIGINT_H

#define DIGITS_NUM 100
#define NEGATIVE   -1
#define POSITIVE   1

typedef struct _st_bigint
{
        int iaValue[ DIGITS_NUM + 1 ];
        int iUsed;
        int iFlag;
} st_bigint;

int get_digits_of_int( unsigned int iInteger );
int str2bigint( const char *ccpStr, st_bigint *stpBigint );
int add_bigint( st_bigint *stpOper1, st_bigint *stpOper2, st_bigint *stpResult );
int print_bigint( st_bigint *stpResult );


#endif



/*
** FILE:    bigint.c
** NOTE:    2015-10-08 created by Jack Liu
*/
#include<stdio.h>
#include<string.h>
#include<limits.h>
#include"bigint.h"

int 
get_digits_of_int( unsigned int iInteger )
{
        int iCnt = 1;

        iInteger = iInteger > 0 ? iInteger : -iInteger;

        while( ( iInteger /= 10 ) > 0 )
                ++iCnt;

        return iCnt;
}

int 
str2bigint( const char *ccpStr, st_bigint *stpBigint )
{
        int iStrLen = strlen( ccpStr );
        int iIntLen = get_digits_of_int( INT_MAX );
        int iTmpInt = 0;
        int iTmpPos = 0;
        int i = 0;

        if( ccpStr[ 0 ] == '-' )
                stpBigint->iFlag = NEGATIVE;
        else
        {
                stpBigint->iFlag = POSITIVE;
                iTmpInt = *( ccpStr ) - '0';
                iTmpPos++;
        }

        for( i = 1; i < iStrLen; ++i )
        {
                iTmpInt = iTmpInt * 10 + *( ccpStr + i ) - '0';
                if( ++iTmpPos == iIntLen - 1 )
                {
                        stpBigint->iaValue[ stpBigint->iUsed++ ] = iTmpInt;
                        iTmpInt = 0;
                        iTmpPos = 0;
                }
        }

        if( iTmpInt > 0 )
                stpBigint->iaValue[ stpBigint->iUsed++ ] = iTmpInt;

        return 0;
}

static int 
get_int_carry( unsigned int uiResult, int iLimLen, int *ipRemain )
{
        int i = 0;
        unsigned int uiTmpResult = uiResult;
        unsigned int uiTmpConvert = 0;

        /*
        ** after for loop, uiTmpResult contain the carry value
        */
        for( i = 0; i < iLimLen; ++i )
                uiTmpResult /= 10;

        /*
        ** build a tmp value with the carry value
        */
        uiTmpConvert = uiTmpResult;
        for( i = 0; i < iLimLen; ++i )
                uiTmpConvert *= 10;

        /*
        ** caculate the remain without the carry part
        */
        if( ipRemain != NULL )
        {
                *ipRemain = uiResult - uiTmpConvert;
        }

        return ( int )uiTmpResult;
}

int 
add_bigint( st_bigint *stpOper1, st_bigint *stpOper2, st_bigint *stpResult )
{
        unsigned int uiTmpResult = 0;
        int iIntLen = get_digits_of_int( INT_MAX );
        int iTmpCarry = 0;
        int iCalcuCnt = stpOper1->iUsed > stpOper2->iUsed ? stpOper2->iUsed : stpOper1->iUsed;
        int iCarryCnt = stpOper1->iUsed > stpOper2->iUsed ? stpOper1->iUsed : stpOper2->iUsed;

        if( stpOper1->iFlag == POSITIVE && stpOper2->iFlag == POSITIVE )
        {
                int i = 0;
                int j = 0;
                int iTmpResultLen = 0;
                stpResult->iUsed = iCarryCnt + 1;
                for( i = iCalcuCnt; i > 0; --i )
                {
                        uiTmpResult = stpOper1->iaValue[ stpOper1->iUsed - 1 - j ] + stpOper2->iaValue[ stpOper2->iUsed - 1 - j ] + iTmpCarry;
                        iTmpCarry = 0;
                        iTmpResultLen = get_digits_of_int( uiTmpResult );
                        if( iTmpResultLen >= iIntLen )
                                iTmpCarry = get_int_carry( uiTmpResult, iIntLen, &( stpResult->iaValue[ stpResult->iUsed - 1 - j ] ) );
                        else
                                stpResult->iaValue[ stpResult->iUsed - 1 - j ] = uiTmpResult;
                        j++;
                } 

                for( i = stpOper1->iUsed - iCalcuCnt, j = 0; i > 0; --i )
                {
                        uiTmpResult = stpOper1->iaValue[ stpOper1->iUsed - 1 - iCalcuCnt - j ] + iTmpCarry;
                        iTmpCarry = 0;
                        iTmpResultLen = get_digits_of_int( uiTmpResult );
                        if( iTmpResultLen >= iIntLen )
                                iTmpCarry = get_int_carry( uiTmpResult, iIntLen, &( stpResult->iaValue[ stpResult->iUsed - 1 - iCalcuCnt - j ] ) );
                        else
                                stpResult->iaValue[ stpResult->iUsed - 1 - iCalcuCnt - j ] = uiTmpResult;
                        j++;
                }

                for( i = stpOper2->iUsed - iCalcuCnt, j = 0; i > 0; --i )
                {
                        uiTmpResult = stpOper1->iaValue[ stpOper2->iUsed - 1 - iCalcuCnt - j ] + iTmpCarry;
                        iTmpCarry = 0;
                        iTmpResultLen = get_digits_of_int( uiTmpResult );
                        if( iTmpResultLen >= iIntLen )
                                iTmpCarry = get_int_carry( uiTmpResult, iIntLen, &( stpResult->iaValue[ stpResult->iUsed - 1 - iCalcuCnt - j ] ) );
                        else
                                stpResult->iaValue[ stpResult->iUsed - 1 - iCalcuCnt - j ] = uiTmpResult;
                        j++;
                }

                if( iTmpCarry > 0 )
                        stpResult->iaValue[ 0 ] = iTmpCarry;
                else
                {
                        for( i = 1; i < stpResult->iUsed; ++i )
                                stpResult->iaValue[ i - 1 ] = stpResult->iaValue[ i ];
                        stpResult->iUsed--;
                }
        }

        return 0;
}

int print_bigint( st_bigint *stpResult )
{
        int i = 0;

        if( stpResult->iFlag == NEGATIVE )
                printf( "-" );

        for( i = 0; i < stpResult->iUsed; ++i )
        {
                printf( "%d", stpResult->iaValue[ i ] );
        }

        return 0;
}

![圖片說明](http://img.ask.csdn.net/upload/201510/09/1444322973_353727.png)