//用链表实现堆栈

/**

* 节点类

*/

class LinkS {

private long data;

public LinkS next;

public LinkS(long d) {

this.data = d;

}

public String toString() {

return String.valueOf(data);

}

}

/**

* 链表类

*/

class LinkSList {

private LinkS first;

public LinkSList() {

first = null;

}

public void insertFirst(LinkS node) {

node.next = first;

first = node;

}

public LinkS deleteFirst() {

LinkS temp = first;

first = first.next;

return temp;

}

public boolean isEmpty() {

return first == null;

}

public String toString() {

if (isEmpty())

return "[]";

StringBuilder sb = new StringBuilder();

sb.append("[");

LinkS curr = first;

while (curr != null) {

sb.append(curr.toString()).append(",");

curr = curr.next;

}

sb.deleteCharAt(sb.length() - 1);

sb.append("]");

return sb.toString();

}

}

/**

* 栈

*/

class LinkStack {

private LinkSList linkList;

public LinkStack() {

this.linkList = new LinkSList();

}

public void push(LinkS l) {

this.linkList.insertFirst(l);

}

public LinkS pop() {

return this.linkList.deleteFirst();

}

public boolean isEmpty() {

return this.linkList.isEmpty();

}

public String toString() {

return this.linkList.toString();

}

public void display() {

System.out.println(toString());

}

}

public class LinkStackDemo {

public static void main(String[] args) {

LinkStack stack = new LinkStack();

for (int i = 0; i < 5; i++) {

LinkS l = new LinkS(i);

stack.push(l);

stack.display();

}

while (!stack.isEmpty()) {

System.out.print("pop出" + stack.pop());

System.out.print("现在栈为:");

stack.display();

}

}

}