resource.c

#include <stdio.h> 
#include <stdlib.h> 

typedef struct {
  char* id;
  int capacity;
} Room;

typedef struct {
  char* fullname;
  char* numberPhone;
} Professor;

typedef struct {
  enum { PROF, ROOM } kind;
  union {
    Room room;
    Professor prof;
  } type;
} Resource;

void print(Resource *resource) {
  switch( resource->kind ){
    case ROOM:
      printf("room id: %s with capacity: %i\n", 
             resource->type.room.id, 
             resource->type.room.capacity);
      break;
    case PROF:
      printf("professeur fullname: %s, numberphone: %s\n", 
             resource->type.prof.fullname, 
             resource->type.prof.numberPhone);
      break;
  }
}

int main() {
  Resource resources[3] = { 
    {.kind = PROF, .type = {.prof.fullname="Paul",.prof.numberPhone="62433"}},
    {.kind = PROF, .type = {.prof.fullname="Oreste",.prof.numberPhone="62422"}},
    {.kind = ROOM, .type = {.room.id="A406", .room.capacity=50}}
  };
  for(int i = 0; i < 3; i++){
    print(&resources[i]);
  }
  return EXIT_SUCCESS;
}