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下面的代碼:通用單鏈接名錄 - 不兼容的類型
import java.util.Scanner;
public class singlyyyyyy<E>{
class Node<E>{
private E element;
private Node<E> next;
public Node(E e, Node<E> n){
element = e;
next = n;
}
public E getElement(){
return element;
}
public Node<E> getNext(){
return next;
}
public void setNext(Node<E> n){
next = n;
}
}
private Node<E> head = null;
private Node<E> tail = null;
int size = 0;
public int size(){
return size;
}
public boolean isEmpty(){
return size == 0;
}
public E first(){
if(isEmpty())
return null;
return head.getElement();
}
public E last(){
if(isEmpty())
return null;
return tail.getElement();
}
public void addFirst(E e){
head = new Node<>(e, head);
if(size == 0)
tail = head;
size++;
}
public void addLast(E e){
Node<E> newNode = new Node<>(e, null);
if(isEmpty())
head = newNode;
else
tail.setNext(newNode);
tail = newNode;
size++;
}
public E removeFirst(){
if(isEmpty())
return null;
E a = head.getElement();
head = head.getNext();
size--;
if(size == 0)
tail = null;
return a;
}
@Override
public String toString() {
StringBuilder buf = new StringBuilder();
buf.append('[');
if (!isEmpty()) {
buf.append(head.getElement());
Node<E> nodeRef = head.getNext();
while (nodeRef != null) {
buf.append(", ");
buf.append(nodeRef.getElement());
nodeRef = nodeRef.getNext();
}
}
buf.append(']');
return buf.toString();
}
public void invoke(){
Scanner scan = new Scanner(System.in);
singlyyyyyy<E> node = new singlyyyyyy<>();
E e;
System.out.print("Enter size : ");
node.size();
System.out.println("----------Menu----------");
System.out.println("1. Add First Element ");
System.out.println("2. Add Last Element ");
System.out.println("3. Remove First ");
System.out.println("4. Display ");
System.out.println("0. Terminate Program ");
System.out.println("------------------------");
int choice = scan.nextInt();
switch(choice){
case 1:
E put;
System.out.println("Add first element: ");
put = scan.next();
node.addFirst(put);
break;
case 2:
E pin;
System.out.println("Add last element: ");
pin = scan.next();
node.addFirst(pin);
break;
case 3:
node.removeFirst();
break;
case 4:
System.out.print(node);
break;
case 0:
System.out.println("\nProgram Terminated.\n");
break;
}
}
}
class Main{
public static void main(){
singlyyyyyy<Integer> singly = new singlyyyyyy<Integer>();
singly.invoke();
}
}
我明白提示用戶時,輸入一個因素,因爲E
是通用的,scan.next();
僅用於對象和字符串我不能使用scan.next();
。我已考慮解析put
和pin
至int
,但addFirst()
和addLast()
只接受E
。
讀取用戶輸入應該不在名單內,但在'主要進行() '方法,並且由於您定義'singly'以使用泛型類型'Integer',只需從用戶輸入創建'Integer'實例。除此之外,請檢查Java代碼規範中關於命名的提示(類名稱應以大寫字母開頭等)。 - 更準確地說,在第一部分中:方法'invoke'()'不應該成爲任何列表/節點實例的一部分。 – Thomas
歡迎來到「upvote level」btw ;-) – GhostCat