/* simple_cat.c */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX 10

typedef struct Animal{
    void *this;
    char name[MAX];
    void (*shout)(struct Animal *); 
}Animal;

typedef struct Cat{
    Animal *animal;
}Cat;

void shout_cat(Animal *cat) {
    printf("%s miaomiao. \n", cat->name);
}

void visit_animal(Animal *animal) {
    animal->shout(animal);
}

void initialize_cat(Cat* cat, char *name) {
    cat->animal = (Animal *) malloc(sizeof(Animal));
    cat->animal->this = cat;
    cat->animal->shout = shout_cat;
    strcpy(cat->animal->name, name);
}

void finalize_cat(Cat *cat) {
    free(cat->animal);
}

void main() {
    Cat cat;
    initialize_cat(&cat, "Kitty");
    visit_animal(cat.animal);
    finalize_cat(&cat);
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//#include <conio.h>
#define MAX 10

typedef struct Animal{
    void *this;
    char name[MAX];
    void (*shout)(struct Animal *); 
}Animal;

typedef struct Swimmable{
    void *this;
    void (*swim)(struct Swimmable *); 
}Swimmable;

typedef struct Dog{
    Animal *Animal;
    Swimmable *Swimmable;
}Dog;

typedef struct Cat{
    Animal *Animal;
    Swimmable *Swimmable;
}Cat;

void shout_Cat(Animal *cat){
    printf("%s miaomiao.\n", cat->name);
}

void swim_Cat(Swimmable *cat){
    printf("%s cannot swim.\n", ((Cat *)(cat->this))->Animal->name);
}

void shout_Dog(Animal *dog){
    printf("%s wangwang.\n", dog->name);
}

void swim_Dog(Swimmable *dog){
    printf("%s can swim.\n", ((Dog *)(dog->this))->Animal->name);
}

void visit_Animal(Animal *animal){
    animal->shout(animal);
}
void visit_Swimmable(Swimmable *swimmable){
    swimmable->swim(swimmable);
}

void initialize_Dog(Dog* dog, char *name){
    dog->Animal = (Animal *) malloc(sizeof(Animal));
    dog->Animal->this = dog;
    dog->Animal->shout = shout_Dog;
    strcpy(dog->Animal->name, name);
    dog->Swimmable = (Swimmable *) malloc(sizeof(Swimmable));
    dog->Swimmable->this = dog;
    dog->Swimmable->swim = swim_Dog;
}

void initialize_Cat(Cat* cat, char *name){
    cat->Animal = (Animal *) malloc(sizeof(Animal));
    cat->Animal->this = cat;
    cat->Animal->shout = shout_Cat;
    strcpy(cat->Animal->name, name);
    cat->Swimmable = (Swimmable *) malloc(sizeof(Swimmable));
    cat->Swimmable->this = cat;
    cat->Swimmable->swim = swim_Cat;
}

void finalize_Dog(Dog *dog){
    free(dog->Animal);
    free(dog->Swimmable);
}

void finalize_Cat(Cat *cat){
    free(cat->Animal);
    free(cat->Swimmable);
}

void main(){
    Dog dog;
    Cat cat;
    //clrscr();
    initialize_Dog(&dog, "Wangcai");
    initialize_Cat(&cat, "Kitty");
    visit_Animal(dog.Animal);
    visit_Animal(cat.Animal);
    visit_Swimmable(dog.Swimmable);
    visit_Swimmable(cat.Swimmable);
    finalize_Dog(&dog);
    finalize_Cat(&cat);
}