My repl is showing linker error. How to resolve?

any program that i execute keeps showing that i am having a linker error.
what can i do to resolve this?

Repl link/Link to where the bug appears:

#define STACKSIZE 100
#define INT 1
#define FLOAT 2
#define STRING 3
struct stackelement {
    int etype;
        int ival;
        float fval;
        char *pavl; //pointer to string
   } element;
struct stack
   int top;// it is the index position of the top element.
   struct stackelement items[STACKSIZE];

int main()
  printf("this is the main loop");
  return 0;

Hi @KarthikSunil1 , welcome to the forums!
You can only have 1 C file at a time, but here is a possible solution from a simllar topic:

Hope this helps!