java实现 单链表 不带头节点 单向

代码已上传至github:

javaCourse/2022_4_28 at frankRenlf-mySingleList · frankRenlf/javaCourse · GitHubhttps://github.com/frankRenlf/javaCourse/tree/frankRenlf-mySingleList/2022_4_28

package mySingleList;

public class MySingleList {

    static class ListNode {
        private int value;
        private ListNode next;

        public ListNode() {
        }

        public ListNode(int value) {
            this.value = value;
        }

        public int getValue() {
            return value;
        }

        public void setValue(int value) {
            this.value = value;
        }

        public ListNode getNext() {
            return next;
        }

        public void setNext(ListNode next) {
            this.next = next;
        }
    }

    public ListNode head;

    public void createList(int n) {
        ListNode node = null;
        for (int i = 0; i < n; i++) {
            if (head == null) {
                head = new ListNode(i);
                node = head;
            } else {
                assert node != null;
                // tmp.setValue(i);
                node.setNext(new ListNode(i));
                node = node.getNext();
            }

        }
    }

    public void displayList() {
        ListNode node = head;
        while (node != null) {
            System.out.print(node.getValue() + " ");
            node = node.getNext();
        }
        System.out.println();
    }

    //头插法
    public void addFirst(int data) {
        ListNode node = new ListNode(data);
        node.setNext(head);
        head = node;
    }

    //尾插法
    public void addLast(int data) {
        if (head == null) {
            head = new ListNode(data);
            return;
        }
        ListNode node = head;
        while (node.getNext() != null) {
            node = node.getNext();
        }
        node.setNext(new ListNode(data));
    }

    //任意位置插入,第一个数据节点为0号下标
    public boolean addIndex(int index, int data) {
        ListNode node = head;
        if (index < 0) {
            return false;
        }
        if (index == 0) {
            addFirst(data);
            return true;
        }
        while (index > 1) {
            if (node.getNext() == null) {
                return false;
            }
            node = node.getNext();
            index--;
        }
        ListNode tmp = node.getNext();
        node.setNext(new ListNode(data));
        node.getNext().setNext(tmp);
        return true;
    }

    //查找是否包含关键字key是否在单链表当中
    public boolean contains(int key) {
        ListNode node = head;
        while (node != null) {
            if (node.getValue() == key) {
                return true;
            }
            node = node.getNext();
        }
        return false;
    }

    //删除第一次出现关键字为key的节点
    public void remove(int key) {
        if (head.getValue() == key) {
            head = head.getNext();
            return;
        }
        ListNode node = head;
        while (node.getNext() != null) {
            if (node.getNext().getValue() == key) {
                node.setNext(node.getNext().getNext());
                return;
            }
            node = node.getNext();
        }
    }

    //删除所有值为key的节点
    public void removeAllKey(int key) {
        while (head.getValue() == key) {
            head = head.getNext();
        }
        ListNode node = head;
        while (node != null && node.getNext() != null) {
            if (node.getNext().getValue() == key) {
                node.setNext(node.getNext().getNext());
            }
            node = node.getNext();
        }
    }

    //得到单链表的长度
    public int size() {
        int size = 0;
        ListNode node = head;
        while (node != null) {
            size++;
            node = node.getNext();
        }
        return size;
    }

    public void clear() {

    }

}

import mySingleList.MySingleList;

public class TestList {

    public static void main(String[] args) {
        MySingleList mySingleList = new MySingleList();
        mySingleList.addLast(1);
        mySingleList.addLast(2);
        mySingleList.addLast(3);
        mySingleList.addLast(1);

        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.removeAllKey(1);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

    }

    public static void main1(String[] args) {
        MySingleList mySingleList = new MySingleList();
        mySingleList.createList(5);

        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.addFirst(12);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.addFirst(22);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.addLast(12);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        System.out.println(mySingleList.addIndex(8, 33));
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        System.out.println(mySingleList.contains(22));
        System.out.println("================");

        mySingleList.remove(33);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.remove(2);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());
        System.out.println("================");

        mySingleList.removeAllKey(12);
        System.out.print("Display: ");
        mySingleList.displayList();
        System.out.println("Size: " + mySingleList.size());

    }

}