《Java数据结构与算法》笔记-CH5-链表-4用链表实现堆栈

  1 //用链表实现堆栈
  2 /**
  3  * 节点类
  4  */
  5 class LinkS {
  6     private long data;
  7     public LinkS next;
  8 
  9     public LinkS(long d) {
 10         this.data = d;
 11     }
 12 
 13     public String toString() {
 14         return String.valueOf(data);
 15     }
 16 }
 17 
 18 /**
 19  * 链表类
 20  */
 21 class LinkSList {
 22     private LinkS first;
 23 
 24     public LinkSList() {
 25         first = null;
 26     }
 27 
 28     public void insertFirst(LinkS node) {
 29         node.next = first;
 30         first = node;
 31     }
 32 
 33     public LinkS deleteFirst() {
 34         LinkS temp = first;
 35         first = first.next;
 36         return temp;
 37     }
 38 
 39     public boolean isEmpty() {
 40         return first == null;
 41     }
 42 
 43     public String toString() {
 44         if (isEmpty())
 45             return "[]";
 46         StringBuilder sb = new StringBuilder();
 47         sb.append("[");
 48         LinkS curr = first;
 49         while (curr != null) {
 50             sb.append(curr.toString()).append(",");
 51             curr = curr.next;
 52         }
 53         sb.deleteCharAt(sb.length() - 1);
 54         sb.append("]");
 55         return sb.toString();
 56     }
 57 }
 58 
 59 /**
 60  * 栈
 61  */
 62 class LinkStack {
 63     private LinkSList linkList;
 64 
 65     public LinkStack() {
 66         this.linkList = new LinkSList();
 67     }
 68 
 69     public void push(LinkS l) {
 70         this.linkList.insertFirst(l);
 71     }
 72 
 73     public LinkS pop() {
 74         return this.linkList.deleteFirst();
 75     }
 76 
 77     public boolean isEmpty() {
 78         return this.linkList.isEmpty();
 79     }
 80 
 81     public String toString() {
 82         return this.linkList.toString();
 83     }
 84 
 85     public void display() {
 86         System.out.println(toString());
 87     }
 88 }
 89 
 90 public class LinkStackDemo {
 91     public static void main(String[] args) {
 92         LinkStack stack = new LinkStack();
 93         for (int i = 0; i < 5; i++) {
 94             LinkS l = new LinkS(i);
 95             stack.push(l);
 96             stack.display();
 97         }
 98         while (!stack.isEmpty()) {
 99             System.out.print("pop出" + stack.pop());
100             System.out.print("现在栈为:");
101             stack.display();
102         }
103     }
104 }