Hello people, I have the doubt of how to start

Question

average , major and minor. Of a variable set
the number of students starts from scratch and the Add grade or Finish option is added, with which the user can add the grades one by one or finish.

Answer 1

Resultado ;
#include<stdio.h>
#include<stdlib.h>
int main(){
    float calificaciones[???];
    float promedio =0;
    int mayor =0;
    int menor =0;
    float media =0;   
    for ( int i=0; i<=??; i++){
    printf ("ingrese  la calificación que quieras %d\n",i );
    scanf ("%f" ,&calificaciones[i]);
    promedio +=calificaciones[i];
 if(calificaciones [i]>calificaciones[mayor]){
 mayor =i;
 }
 }
   for(int i=0; i<??; i++){
    if(calificaciones [i]< calificaciones [menor]){

        menor=i;   
    }
media = (promedio + calificaciones [i])/2;
}
printf  ("el medio es %2.f\n" , media );
printf ("el promedio es: %2.f\n" ,promedio );                       
printf("calificacion menor: %d\n", menor);
printf("\n esta en la posicion: %d\n",menor);
printf("calificacion mayor: %d\n", mayor);
printf("\n esta en la posicion: %d\n",mayor);
return 0;
}

Answer 2

How would I add note and end
And starting at 0

Answer 3

Any advice would be appreciated