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| 9. 50. 4. 清单实现的栈 |
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class Link {
public int iData;
public Link next;
public Link(int id) {
iData = id;
}
public String toString() {
return "{" + iData + "} ";
}
}
class LinkList {
private Link first;
public LinkList() {
first = null;
}
public boolean isEmpty() {
return (first == null);
}
public void insertFirst(int dd) {
Link newLink = new Link(dd);
newLink.next = first;
first = newLink;
}
public int deleteFirst() {
Link temp = first;
first = first.next;
return temp.iData;
}
public String toString() {
String str="";
Link current = first;
while (current != null) {
str += current.toString();
current = current.next;
}
return str;
}
}
class LinkStack {
private LinkList theList;
public LinkStack() {
theList = new LinkList();
}
public void push(int j) {
theList.insertFirst(j);
}
public double pop() {
return theList.deleteFirst();
}
public boolean isEmpty() {
return (theList.isEmpty());
}
public String toString() {
return theList.toString();
}
}
public class MainClass {
public static void main(String[] args) {
LinkStack theStack = new LinkStack();
theStack.push(20);
theStack.push(40);
System.out.println(theStack);
theStack.push(60);
theStack.push(80);
System.out.println(theStack);
theStack.pop();
theStack.pop();
System.out.println(theStack);
}
}
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{40} {20}
{80} {60} {40} {20}
{40} {20} |
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