程序代码：

#include<stdio.h>
main()

 {
   int a[10]={0,0,0,0,0,0,0,0,0,0};
   int digit;
   int n;
   for(;;)
    {
   printf("Enter a number: ");
   scanf("%d", &n);
   if(n<=0)
   break;
   while(n>0)
        {
    digit=n%10;
    if(a[digit])
     break;
    a[digit]=1;
    n/=10;
        }
    if(n>0)
     printf("Repeated digit\n");
    else
     printf("No repeated digit\n");
    }

 }