《Java数据结构与算法》笔记-CH5-链表-1单链表

/**
* Link节点
* 有数据项和next指向下一个Link引用
*/
class Link {
private int iData;//数据
private double dData;//数据
public Link next;//下一个link节点的引用

public Link(int i, double d) {
iData = i;
dData = d;
}

public String toString() {
return "[" + iData + "," + dData + "]";
}

public void displayLink() {
System.out.println(toString());
}
}
/**
* 链表类
* 维护一个头节点
*/
class LinkList {
private Link first;
/**
* 初始化的时候头结点置空
*/
public LinkList() {
first = null;
}
/**
* 头结点是空代表链表为空
* @return
*/
public boolean isEmpty() {
return first == null;
}
/**
* 向链表头插入Link节点
* @param link
*/
public void insertFirst(Link link) {
link.next = first;//要插入的节点的next指针指向链表的头节点
first = link;//链表的头结点指向被插入的节点
}
/**
* 从链表头删除头结点并返回
* @return
*/
public Link deleteFirst() {
Link temp = first;//temp临时存上头结点
first = first.next;//将头节点的next指针指向下一个节点
return temp;//返回temp
}

@Override
public String toString() {
if (isEmpty())
return "{}";
StringBuilder sb = new StringBuilder();
sb.append("{");
Link current = first;
while (current != null) {
sb.append(current.toString());
sb.append(",");
current = current.next;
}
sb.deleteCharAt(sb.length() - 1);
sb.append("}");
return sb.toString();
}

public void displayList() {
System.out.println(toString());
}
}

public class LinkListDemo {
public static void main(String[] args) {
LinkList ll = new LinkList();
for (int i = 0; i < 10; i++) {
Link l = new Link(i, i + 11.23);
ll.insertFirst(l);
ll.displayList();
}
ll.deleteFirst();
ll.deleteFirst();
ll.displayList();
}
}