Subsets in C programming, Where is the problem_

[Lebron]

Hi, I was trying to write a C program that lists all of the subsets of the set {1,2,...,n}. The program should be ask number of elements in the set from the keyboard, and the order must be shown in the example.

For example;
Enter the number of elements: 3
The subsets of {1,2,3} are :
1.<Empty set>
2. {1}
3. {2}
4. {3}
5. {1,2}
6. {1,3}
7. {2,3}
8. {1,2,3}

Here is my codes, I have trouble, when I entered 5,4, or 3. (Basiccally entered>=3) It doesnt show all subsets, I spend too much time for this code and I dont wanna get bad grade. Can anybody help me to fix this code, Where şs the problem, and how to fix it?

#include <stdio.h>
int main()
{
    int sayi, subset, i, j, start, index, a[50], x;
    printf("Enter the number of elements :");
    scanf("%d", &sayi);
     
    for(x = 0; x < sayi; x++)
    {
        a[x] = x + 1;
    }
    
    printf("The subsets are :\n");
    
    for(subset = 1; subset <= sayi; subset++)

    {

      for(start = 0; start <= sayi - subset; start++)

        {
            if(subset == 1)
            {
                printf("{%d}\n", a[start]);
            }
           else
            {
               index = start + subset - 1;
        for(j = index; j < sayi; j++)
                {
                    for(i = start; i < index; i++)
                    {
                        printf("{%d}", a[i]);
                    }
                  printf("{%d}\n", a[j]);
                }
            }
        }
    }
   printf("{ }");
   /* main() is supposed to return a value */
    return 0;
}