编辑代码

#include <stdio.h>
int main ()
{
 int a,b,m;
 printf ("请输入两个相减的数\n");
 scanf ("%d-%d",&a,&b);
    if (a<=100&&b<=100)
       { if(a>=0&&b>=0)
         m=a-b;
           if ((a<10&&b<10)||(a>10&&b>10))
            { printf ("    %d\n",a);
            printf (" -  %d\n",b);
            printf ("-------\n");
            printf (" =   %d\n",m);
            }
            else 
            if (a>b)
            { printf ("    %d\n",a);
            printf (" -   %d\n",b);
            printf ("-------\n");
            printf ("  =  %d\n",m); 
            }
            if (a<b)
            { printf ("     %d\n",a);
            printf ("    -%d\n",b);
            printf ("---------\n");
            printf (" =  %d\n",m) ;
            printf ("前面的数不够减后面的数\n");}
       }
    else 
            { if(a>100||a<0)
             printf ("第一数字输入错误，请重新输入:\n");
            else 
             printf ("第二个数输入错误，请重新输入:\n");
            }
    
    return 0;
}