java第一题

package zxd0001;
import java.util.Scanner;
abstract class Animal{
public static int count=0;
Animal(){System.out.printf("Animal\n");count=count+1;
}
public static void getcount() {
System.out.printf("Animal:%d\n",count);
}
abstract void speak();
protected void finalize() {count=count-1;};
}
class Dog extends Animal{
public static int count=0;
Dog(){ super();System.out.printf("Dog\n");count=count+1;}
public static void getcount() {
System.out.printf("Dog:%d\n",count);

}
void speak() {System.out.printf("wang\n");};
protected void finalize() {super.finalize();count=count-1;};
}
class Cat extends Animal{
public static int count=0;
Cat(){
super();
System.out.printf("Cat\n");count=count+1;}
public static void getcount() {
System.out.printf("Cat:%d\n",count);
}
void speak( ) { System.out.printf("miao\n");};
protected void finalize() {super.finalize();count=count-1;};
}
public class A001 {
public static void main(String args[]){
int n,m,i=0;
Scanner sc = new Scanner(System.in);
n= sc.nextInt();
m= sc.nextInt();
Animal[] a=new Animal[20];

for (; i < n; i++) {
a[i]=new Dog();
}
Animal.getcount();
Dog.getcount();

for ( ; i < n+m; i++) {
a[i]=new Cat();
}
Animal.getcount();
Cat.getcount();

for (int j = 0; j < n+m-3; j++) {//总量小于3时，不做删除
a[j].speak();
a[j].finalize();
}
Animal.getcount();
Dog.getcount();
Cat.getcount();
}
}