#include <stdio.h>
#include <stdlib.h>
#include<string.h>
void deal(char *a,int  *a1){
  int i,j;
    scanf("%s",a);
    for(i=0;a[i]<='9'&&a[i]>='0';i++)
         a1[i]=a[i]-'1'+1;
}

int main(){
    char a[1010]={0},b[1010]={0};
    int a1[1010]={0},b1[1010]={0},c[1010]={0};
    int i,j,m,n,p,a2,b2,f=1009,sb=0,ars,a3,b3;
    scanf("%d",&n);
    for(p=1;p<=n;p++){
        a2=b2=a3=b3=sb=0,f=1009;
        deal(a,a1),deal(b,b1);
     for(i=0;i<1000&&a[i]!=0;i++)
     a3=a2=i;
     for (i=0;i<1000&&b[i]!=0;i++)
      b3=b2=i;
     while(a2>=0&&b2>=0){
         c[f]=(a1[a2]+b1[b2]+sb)%10;
         sb=(a1[a2]+b1[b2]+sb)/10;
         a2--,b2--;
         f--;
     }
     if(a2>b2){
         while(a2>=0){
             c[f]=(a1[a2]+sb)%10;
             sb=(a1[a2]+sb)/10;
             a2--;
             f--;
         }
     }
    else{
        while(b2>=0){
            {
             c[f]=(b1[b2]+sb)%10;
             sb=(b1[b2]+sb)/10;
             b2--;
             f--;
         }
        }
        if(sb) c[f]=sb,f--;
        printf("case %d:\n",p);
    printf("%s + %s = ",a,b);
     for(i=f+1;i<=1009;i++)
           printf("%d",c[i]);
           if(p==n)
           printf("\n");
           else
           printf("\n\n");
    }
    }
    return 0;
}

你没发现 a比 b大的时候没有输出么？

谢了，我改了，还是过不了啊，为什么啊，
#include <stdio.h>
#include <stdlib.h>
#include<string.h>
void deal(char *a,int  *a1){
  int i,j;
    scanf("%s",a);
    for(i=0;a[i]<='9'&&a[i]>='0';i++)
         a1[i]=a[i]-'1'+1;
}

int main(){
    char a[1010]={0},b[1010]={0};
    int a1[1010]={0},b1[1010]={0},c[1010]={0};
    int i,j,m,n,p,a2,b2,f=1009,sb=0,ars,a3,b3;
    scanf("%d",&n);
    for(p=1;p<=n;p++){
        a2=b2=a3=b3=sb=0,f=1009;
        deal(a,a1),deal(b,b1);
     for(i=0;i<1010&&a[i]!=0;i++)
     a3=a2=i;
     for (i=0;i<1010&&b[i]!=0;i++)
      b3=b2=i;
     while(a2>=0&&b2>=0){
         c[f]=(a1[a2]+b1[b2]+sb)%10;
         sb=(a1[a2]+b1[b2]+sb)/10;
         a2--,b2--;
         f--;
     }
     if(a2>b2){
         while(a2>=0){
             c[f]=(a1[a2]+sb)%10;
             sb=(a1[a2]+sb)/10;
             a2--;
             f--;
         }
     }
    else{
        while(b2>=0){
            {
             c[f]=(b1[b2]+sb)%10;
             sb=(b1[b2]+sb)/10;
             b2--;
             f--;
         }
        }
    }
        if(sb) c[f]=sb,f--;
    printf("case %d:\n",p);
    printf("%s + %s = ",a,b);
     for(i=f+1;i<=1009;i++)
           printf("%d",c[i]);
           if(p==n)
           printf("\n");
           else
           printf("\n\n");

    }
    return 0;
}

不知道了，应该没问题的，你加上负数的情况看看

那个说了是正数的

搞不明白，不懂。你自己测试看看

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

#define MAX 1024

void Add(char *a, char *b, char *c)
{
    int Result, i = 0;
    int a_len = strlen(a);
    int b_len = strlen(b);
    
    memset(c, 0, MAX);

    for (--b_len;--a_len >= 0 && b_len >= 0;--b_len)
    {
        Result = a[a_len]-'0' + b[b_len]-'0' + c[i];
        c[i++] = Result % 10 + '0';
        c[i] = (Result /= 10);
    }
    while (a_len >= 0)
    {
        Result = a[a_len--]-'0' + c[i];
        c[i++] = Result % 10 + '0';
        c[i] = (Result /= 10);
    }
    while (b_len >= 0)
    {
        Result = b[b_len--]-'0' + c[i];
        c[i++] = Result % 10 + '0';
        c[i] = (Result /= 10);
    }
    
    if (Result)    c[i] += '0';
    strrev(c);
}

int main()
{
    int n, i = 0;
    char a[MAX] = {0};
    char b[MAX] = {0};
    char c[MAX] = {0};

    
    for (scanf("%d", &n); ++i <= n;)
    {
        scanf("%s%s", a, b), Add(a, b, c);
        printf("Case %d:\n%s + %s = %s\n", i, a, b, c);
        if (n != i)    puts("");
    }
    return 0;
}