一道java语言题目

来源：百度知道 编辑：UC知道 时间：2024/06/26 03:11:44
若一头小母牛,从第四个年头开始每年生一头母牛.按此规律,第N年时有多少头牛?

母牛类
public class TestCow {

private int age;
private String name;

public TestCow(String name,int age){

this.age=age;
this.name=name;

}

public String getName() {
return name;
}

public void setName(String name) {
this.name = name;
}

public TestCow(String nname){

this.age=0;
this.name=nname;
}
public TestCow addAge(){

age++;
if(age<4){
return null;
}
else{

return makeChild();
}
}

public TestCow makeChild(){

TestCow child=new TestCow(name+"c");

return child;
}
}
农场类
public class Farm {

private List<TestCow> cows=new ArrayList<TestCow>();

public Farm(int num){
for(int i=0;i<num;i++){

TestCow cow= new TestCow("Cow&