Java链表数据结构及其简单使用方法解析

public class Node {
    public int value;
    public Node next;
    
    public Node(int value) {
        this.value = value;
    }
}

public class DoubleNode {
    public int value;
    public DoubleNode pre;
    public DoubleNode next;
    
    public DoubleNode(int value) {
        this.value = value;
    }
}

public static Node reverseNode(Node head) {
    Node pre = null;
    Node next = null;
    //最终让head指向null
    while (head != null) {
        next = head.next;
        head.next = pre;
        pre = head;
        head = next;
    }
    return pre;
}

public DoubleNode reverseDoubleNode(DoubleNode head) {
    DoubleNode pre = null;
    DoubleNode next = null;
    while (head != null) {
        next = head.next;
        //操作（移动）当前节点
        head.next = pre;
        head.pre = next;

        pre = head;
        head = next;
    }
    return pre;
}

//head移动到第一个不需要删除的位置：边界条件
while (head != null) {
    if (head.value != num) {
        break;
    }
    //head右移
    head = head.next;
}
//跳出循环之后，head的情况：
//1. head = null，这种情况是链表中的值全部是给定值，全删了
//2. head != null
// 中间操作
//最终返回head：第一个不是给定值的节点
return head;

Node pre = head;
Node cur = head;
while (cur != null) {
    if (cur.value == num) {
        pre.next = cur.next;
    } else {
        pre = cur;
    }
    cur = cur.next;
}

public static Node remove (Node head, int num) {
    while (head != null) {
        if (head.value != num) {
            break;
        }
        head = head.next;
    }

    Node pre = head;
    Node cur = head;

    while (cur != null) {
        if (cur.value == num) {
            pre.next = cur.next;
        } else {
            pre = cur;
        }
        cur = cur.next;
    }
    return head;
}