AC代碼：

#include <iostream>
#include <cstdio>
#include <cstring>
#define Max 1050
using namespace std;

void hanshu(char *s1,char *s2,char *s);

int main(void)
{
    freopen("in.txt","r",stdin);
    int T,count=0;
    char s1[Max],s2[Max],s[Max];
    scanf("%d",&T);
    while(T--)
    {
        scanf(
 
"%s%s",s1,s2);
        hanshu(s1,s2,s);
        count++;
        if(T!=0)
            printf("Case %d:\n%s + %s = %s\n\n",count,s1,s2,s);    
        else
            printf("Case %d:\n%s + %s = %s\n",count,s1,s2,s);    
    }

    fclose(stdin);
    return 0;
}

void hanshu(char *s1,char*s2,char *s)
{
    
 
int length1=strlen(s1),length2=strlen(s2),length;
    if(length1>length2)
        length=length1;
    else
        length=length2;
    s[length+1]=‘\0‘;
    s[0]=‘0‘;
    int a=0,i;
    for(i=length;length1&&length2;i--)
    {
        a=(s1[--length1]-‘0‘)+(s2[--length2]-‘0‘)+a/10;
        s[i]=a%10
 
+‘0‘;
    }
    while(length1)
    {
        a=(s1[--length1]-‘0‘)+a/10;
        s[i--]=a%10+‘0‘;
    }
    while(length2)
    {
        a=(s2[--length2]-‘0‘)+a/10;
        s[i--]=a%10+‘0‘;
    }
    s[i]=a/10+‘0‘;
    
    int t=0;
    while(s[t]==‘0‘&&t<length)
        t++;
    strcpy(s,s+t);
}

HDOJ_1002