#include <stdio.h>
int main()
{
    int *a;//是不是这里用指针，等下就可以用realloc了。
    int *b;
    int i=0,j=0,k;
    printf ("请输入第一个数组:\n");
   
     while (  scanf("%d",&a[i])==1&&a[i]!='\n')
     {
         i++;
     }
     a[i]='\0';
     printf ("输入第二个数组:\n");
     while (scanf("%d",&b[j])==1&&b[i]!='\n')
     {
         j++;
     }
     b[i]='\0';
     j--;
     k=i+j;
     a=(int *)realloc(a,k*sizeof(int));//用realloc 怎么扩充之前的数组同时又
     i=0;不覆盖之前的数组？
     j=0;
     while (i<k)
     {
         while (a[i]!='\0'&&b[j]!='\0')
         {
             if(a[i]<b[j])
             {
                 i++;
             }
             else if(a[i]>b[j])
             {
                 a[i++]=b[j++];
             }
             else
             {
                 i++;
                 j++;
             }
         }
         while (a[i]!='\0')
         {
             i++;
         }
         while(b[j]!='\0')
         {
             a[i++]=b[j++];
         }
     }
         i=0;
         while (a[i]!='\0')
         printf ("%d",a[i]);
         return 0;
}