java单链表基本操作

Myth丶恋晨 2022-01-22 11:59 242阅读 0赞

public class ListNodeDemo { 
        public static void main(String[] args) { 
            ListLinkedList linkedList = new ListLinkedList();
            linkedList.addNode(1);
            linkedList.addNode(3);
            linkedList.addNode(9);
            System.out.println("头插法插入节点:");
            linkedList.printList();
            System.out.println("-----------------------");
            //linkedList.deleteFirst();
            //System.out.println("删除第一个元素");
            //linkedList.printList();
            Object obj = linkedList.findNode(3);
            System.out.printf("查找值为%d的节点:%d\n", 3, obj);
            System.out.println("删除指定值的节点:");
            linkedList.removeNode(3);
            linkedList.printList();
            System.out.println("尾部插入元素:");
            linkedList.addNodeTwo(1111);
            linkedList.printList();
         
        }
    }
    
    class ListLinkedList { 
        /* 构建空的链表,即头节点 */
        ListNode listNode = new ListNode();
    
        ListNode head = listNode.head;
    
        /** * 判断链表是否为空 * * @return */
        public boolean isEmpty() { 
            return head == null;
        }
    
        /** * 添加结点(头插法) * * @param data */
        public void addNode(Object data) { 
            ListNode node = new ListNode(data);
            node.next = head;
            head = node;
        }
    
        /** * 添加节点(尾部添加) * @param data */
        public void addNodeTwo(Object data) { 
            ListNode temp = head;
            ListNode node = new ListNode(data);
            //链表还未有节点时
            if (temp.next == null) { 
                node.next = head;
            } else { 
                while (temp.next != null) { 
                    temp = temp.next;
                }
                temp.next = node;
            }
        }
    
        /** * 删除结点(从头部删除) */
        public void deleteFirst() { 
            if (head == null) { 
                System.out.println("链表为空，无法删除!");
                return;
            }
            ListNode temp = head;
            head = head.next;
        }
    
        /** * 查找指定值的节点,并返回 * * @param obj * @return */
        public Object findNode(Object obj) { 
            if (head == null) { 
                try { 
                    throw new Exception("链表为空!");
                } catch (Exception e) { 
                    e.printStackTrace();
                }
            }
            ListNode cur = head;
            while (cur != null) { 
                if (cur.value == obj) { 
                    return cur.value;
                }
                cur = cur.next;
            }
            return null;
    
        }
    
        /** * 移除指定值的节点 * * @param obj */
        public void removeNode(Object obj) { 
            if (isEmpty()) { 
                System.out.println("链表为空!");
                return;
            }
            if (head.value == obj) { 
                head = head.next;
            } else { 
                ListNode pre = head;
                ListNode cur = head.next;
                while (cur != null) { 
                    if (cur.value == obj) { 
                        pre.next = cur.next;
                    }
                    pre = cur;
                    cur = cur.next;
                }
            }
        }
    
        /** * 打印链表信息 */
        public void printList() { 
            if (head.next == null) { 
                System.out.println("链表为空!");
                return;
            }
            ListNode temp = head;
            while (temp.next != null) { 
                System.out.print(temp.value + "->");
                temp = temp.next;
            }
            System.out.println(temp.value);
        }
    
    }
    
    /** * 定义链表的数据结构 */
    class ListNode { 
        public ListNode next = null;
        public Object value;
    
        public ListNode head = null;
    
        public ListNode() { 
            this.value = null;
            this.value = null;
        }
    
        public ListNode(Object x) { 
            this.value = x;
            this.next = null;
        }
    }

运行结果:

头插法插入节点:
    9->3->1
    -----------------------
    查找值为3的节点:3
    删除指定值的节点:
    9->1
    尾部插入元素:
    9->1->1111