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如何通过递归显示链表中的元素?

linked-list recursion java

Blebhebhe · 技术社区 · 7 年前

您好,这是我的链表,没有实现java。util。双链表

我想创建一个递归显示链表中所有元素的方法,但我不知道如何创建,我的方法没有任何参数,所以在调用方法本身时,我不知道如何获取下一个值

    public class Pokemon {
        private String name;
        private String type;
        private int niveau;

        public Pokemon(String name, String type) {
            this.name = name;
            this.type = type;
            this.niveau = (int) (Math.random() * (1 * 1 - 100) + 100);
        }
        public void display() {
            System.out.println(this.name);
       }

    public class Trainer {

        public final String name;
        private Pokeball head;

        public Trainer(String name) {
            this.name = name;
        }

        public void addPokemon(Pokemon pok) {
            if (this.head != null) {
                this.head.addPokemon(pok);
            } else {
                this.head = new Pokeball(pok);
            }
        }

       public void display() {
            if (this.head == null)
        return;
    else {
        this.head.display();
    }


    }

    public class Pokeball {

        private Pokemon pok;
        private Pokeball next;

        public Pokeball(Pokemon pok) {
            this.pok = pok;
        }

        public Pokeball(Pokemon pok, Pokeball next) {
            this.pok = pok;
            this.next = next;
        }

        public void addPokemon(Pokemon pok) {
            Pokeball current = this;
            while (current.next != null) {
                current = current.next;
            }
            current.next = new Pokeball(pok);
        }

public void display() {
    Pokeball current = this;
    if (current.next == null){
        return;
    } else { 
        // ....
    }


    }

2 回复 | 直到 7 年前

SomeDude 7 年前

我想这是 Pokeball 类,为什么要使用递归显示?为什么不迭代?你的 Trainer 类不创建链表,它没有 next .

public void display() {
    Pokeball current = this; //Note that this won't change your 'this'
    while ( current != null ) {
        System.out.print( current.display() + "->" );
        current = current.next;
    }
}

递归:

private void display_recurse( Pokeball current ) {
    if ( current == null )
      return;
    System.out.print( current.display() + "->" );
    display_recurse( current.next);
}

您可以这样称呼它:

public void display() {
   display_recurse( this );
}

cst1992 7 年前

通常,这是通过使用具有参数的私有助手函数来实现的。

public void display() {
    Pokeball current = this;
    display(current);
}

private void display(Pokeball toDisplay) {
    if(toDisplay == null) {
        return;
    } else {
        // code to display current here
        // ...
        display(toDisplay.next);
    }
}