package day12;
public class LinkedList {
public static void main(String[] args) {
//测试功能
LinkedList list = new LinkedList();
list.insert(0, 1);
list.add("asd");
list.add(123);
list.add("111111");
list.add("55555555555555");
list.insert(3, 12);
list.remove("asd");
list.find(123);
list.print();
}
public static class ListNode {
Object date;
ListNode next;
public ListNode(Object date) {
this.date = date;
}
}
ListNode head;
ListNode end;
int size;
public LinkedList() {
head = null;//头节点
end = null;//尾节点
size = 0;//链表中节点个数
}
//在末尾加入一个节点
public void add(Object date) {
ListNode newNode = new ListNode(date);
if (end == null) {
end = newNode;
} else {
end.next = newNode;
end = newNode;
}
size++;
}
public void insert(int position, Object date) {
if (position > size) {
return;
}
ListNode newNode = new ListNode(date);
//当插入的位置是头节点时
if (position == 0) {
newNode.next = head;
head = newNode;
//当插入的位置是头节点且尾节点为null（也就是链表是空的的时候）
if (end == null) {
end = newNode;
}
size++;
} else if (position == size) {
//如果是在末尾插入
this.add(date);
} else {
/**如果是在中间位置插入
* 找到目标位置的前一个节点
*/
ListNode a = head;
for (int i = 0; i < position - 1; i++) {
if (a.next == null) {
break;
}
a = a.next;
}
ListNode b = a.next;
newNode.next = b;
a.next = newNode;
size++;
}
}
public void remove(Object date) {
//如果要删除的是头节点
if (head != null && head.date == date) {
head = head.next;
size--;
if (size == 0) {
head = end;
}
} else {
ListNode a = head;
ListNode b = a.next;
while (b != null) {
if (b.date == date) {
//如果要删除的是尾节点
if (b == end) {
end = a;
} else {
a.next = b.next;
size--;
return;
}
}
}
}
}
public void find(Object date) {
ListNode a = head;
for (int i = 0; a != null; i++) {
if (a.date == date) {
System.out.println("第" + i + "个节点");
break;
}
a = a.next;
}
}
public void print() {
ListNode a = head;
while (a != null) {
System.out.print(a.date + ",");
a = a.next;
}
}
}
