旧代码 - 高精度加法

#include <stdio.h>
#include <string.h>
#include <memory.h>

int    flag = 0 , cnt = 1;
int    casenum,buf,res,bit,aLen,bLen;
char   a[1001],b[1001],answer[1001];

int main()
{
    register int i,j;
    
    scanf("%d", &casenum);
    while (casenum--)
    {
        getchar();
        scanf("%s %s", a,b);
        
        aLen = strlen(a);
        bLen = strlen(b);
        bit = aLen > bLen? aLen : bLen;
        
        memset(answer,0,sizeof(answer));
        for (i=0; i<aLen; ++i)
            answer[i] = a[aLen-i-1] - '0';

        for (i=0; i<bLen; ++i)
            answer[i] += b[bLen-i-1] - '0';
        
        for (i=0; i<=bit; ++i)
        {
            if (answer[i] > 9)
            {
                answer[i+1] += answer[i] / 10;
                answer[i] %= 10;
            }
        }
        
        if (flag)
        {
            printf("\n");
        }
        flag = 1;
        
        printf("Case %d:\n",cnt++);
        for (i=0; i<aLen; ++i)
        {
            printf("%c", a[i]);
        }
        printf(" + ");
        for (i=0; i<bLen; ++i)
        {
            printf("%c", b[i]);
        }
        printf(" = ");
        
        bit = answer[bit]? bit : bit-1;
        for (i=bit; i>=0; --i)
        {
            printf("%c",answer[i]+'0');
        }
        printf("\n");
    }
    return 0;
}