新增尾結點

LNode LListAddEnd(LNode head, Data data) {
    LNode node = new LNode(), temp;
    node.data = data;   //賦給結點資料
    node.nextNode = null;   //末尾元素，指向null
    if (head == null) {
        head = node;
        return head;
    }
    temp = head;
    while (temp.nextNode != null) {    //查詢連結串列的末尾
        temp = temp.nextNode;
    }
    temp.nextNode = node;     //插入資料放在末尾
    return head;
}
 

新增首節點

LNode LListAddFirst(LNode head, Data data) {
    LNode node = new LNode();
    node.data = data;
    if (head == null) {
        head = node;
        return head;
    }
    node.nextNode = head;
    head = node; //新結點作為head
    return head;
}

查詢結點

LNode LListFind(LNode head, int position) {
    if (position < 0)
        return null;
    LNode temp = head;
    int i = 0;
    while (temp != null) {
        temp = temp.nextNode;
        i++;
        if (i == position)
            return temp;
    }
    return null;
}
 

插入結點

LNode LListInsert(LNode head, int position, Data data) {
    LNode node = new LNode(), temp = new LNode();
    node.data = data;
    //position==0
    if (position == 0) {
        node.nextNode = head; //新結點指向舊head
        head = node;           //新結點作為head
        return head;
    }
    //position!=0
    LNode preNode = LListFind(head, position - 1); //查詢插入位置的前一個結點
    if (preNode != null) {
        node.nextNode = preNode.nextNode;   //將前一個結點的指標給這個新的結點的指標
        preNode.nextNode = node;    // 將前一個結點指向新結點
        return head;
    } else {
        System.out.println("插入位置非法");
        return null;
    }
}
 

刪除結點

LNode LListDelete(LNode head, int position) {
    if (position == 0) {
        return head.nextNode;
    }
    LNode preNode = LListFind(head, position - 1); //查找出前一個結點
    preNode.nextNode = preNode.nextNode.nextNode; //前一個結點指向其下下個結點
    return head;
}

計算連結串列長度

int LListLength(LNode head) {
    LNode temp = head;
    int i = 0;
    while (temp != null) {
        i++;
        temp = temp.nextNode;
    }
    return i;
}

顯示所有結點

void LListShow(LNode head) {
    LNode temp = head;
    while (temp != null) {
        System.out.println(temp.data);
        temp = temp.nextNode;
    }
}

整例

package LinkedList;

import java.util.Objects;
import java.util.Scanner;

/**
 * Description
 * Author cloudr
 * Date 2020/7/25 18:56
 * Version 1.0
 **/
class Data {
    String id;
    String name;
    int age;

    public Data(String id, String name, int age) {
        this.id = id;
        this.name = name;
        this.age = age;
    }

    public Data() {
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Data data = (Data) o;
        return age == data.age &&
                Objects.equals(id, data.id) &&
                Objects.equals(name, data.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, name, age);
    }

    @Override
    public String toString() {
        return "Data{" +
                "id='" + id + '\'' +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

class LNode {
    Data data;
    LNode nextNode; //指向下一個結點

    //新增尾結點
    LNode LListAddEnd(LNode head, Data data) {
        LNode node = new LNode(), temp;
        node.data = data;   //賦給結點資料
        node.nextNode = null;   //末尾元素，指向null
        if (head == null) {
            head = node;
            return head;
        }
        temp = head;
        while (temp.nextNode != null) {    //查詢連結串列的末尾
            temp = temp.nextNode;
        }
        temp.nextNode = node;     //插入資料放在末尾
        return head;
    }

    //新增首節點
    LNode LListAddFirst(LNode head, Data data) {
        LNode node = new LNode();
        node.data = data;
        if (head == null) {
            head = node;
            return head;
        }
        node.nextNode = head;
        head = node; //新結點作為head
        return head;
    }

    //查詢結點
    LNode LListFind(LNode head, int position) {
        if (position < 0)
            return null;
        LNode temp = head;
        int i = 0;
        while (temp != null) {
            temp = temp.nextNode;
            i++;
            if (i == position)
                return temp;
        }
        return null;
    }

    //插入結點
    LNode LListInsert(LNode head, int position, Data data) {
        LNode node = new LNode(), temp = new LNode();
        node.data = data;
        //position==0
        if (position == 0) {
            node.nextNode = head; //新結點指向舊head
            head = node;           //新結點作為head
            return head;
        }
        //position!=0
        LNode preNode = LListFind(head, position - 1); //查詢插入位置的前一個結點
        if (preNode != null) {
            node.nextNode = preNode.nextNode;   //將前一個結點的指標給這個新的結點的指標
            preNode.nextNode = node;    // 將前一個結點指向新結點
            return head;
        } else {
            System.out.println("插入位置非法");
            return null;
        }
    }

    //刪除結點
    LNode LListDelete(LNode head, int position) {
        if (position == 0) {
            return head.nextNode;
        }
        LNode preNode = LListFind(head, position - 1); //查找出前一個結點
        preNode.nextNode = preNode.nextNode.nextNode; //前一個結點指向其下下個結點
        return head;
    }

    //計算連結串列長度
    int LListLength(LNode head) {
        LNode temp = head;
        int i = 0;
        while (temp != null) {
            i++;
            temp = temp.nextNode;
        }
        return i;
    }

    //顯示所有結點
    void LListShow(LNode head) {
        LNode temp = head;
        while (temp != null) {
            System.out.println(temp.data);
            temp = temp.nextNode;
        }
    }

}

public class LinkedList {
    public static void main(String[] args) {
        System.out.println("連結串列測試 輸入結點資訊：（id name age） age為0截止輸入");
        Scanner input = new Scanner(System.in);
        LNode head = null, node = null;
        LNode list = new LNode();
        do {
            Data data = new Data(input.next(), input.next(), input.nextInt());
            if (data.age == 0)
                break;
            head = list.LListAddEnd(head, data);

        } while (true);

        System.out.println("--初始資料--");
        list.LListShow(head);
        head = list.LListAddFirst(head, new Data("6", "6", 6));
        System.out.println(head.data);
        System.out.println("--新增首節點--");
        list.LListShow(head);

        System.out.println("--查詢資料--");
        LNode find = list.LListFind(head, 2);
        System.out.println(find.data);

        System.out.println("--插入結點--");
        list.LListShow(head);

        System.out.println("--連結串列長度--");
        System.out.println(list.LListLength(head));

        System.out.println("--刪除結點--");
        list.LListShow(list.LListDelete(head, 3));
    }
}