在单链表类后面新增 void reverse()和 Node reverse(Node p)方法
代码如下:
package com.apesblog.ReverseLinkList1;
import java.util.Iterator;
import javax.swing.text.html.HTMLDocument.HTMLReader.PreAction;
public class ReverseLinkList1<T> implements Iterable<T> {
private Node head;
private int N;
private class Node {
private T item;
private Node next;
public Node(T item, Node next) {
this.item = item;
this.next = next;
}
}
public ReverseLinkList1() {
this.head = new Node(null, null);
N = 0;
}
public T get(int i) {
if (i < 1 || i > N) {
throw new RuntimeException("查询位置不正确");
}
Node p = head;
for (int index = 1; index <= i; index++) {
p = p.next;
}
return p.item;
}
public void add(T t) {
Node p = head;
while (p.next != null) {
p = p.next;
}
p.next = new Node(t, null);
N++;
}
public void insert(int i, T t) {
if (i < 1 || i >= N) {
throw new RuntimeException("插入位置不正确");
}
Node p = head;
for (int index = 1; index < i; index++) {
p = p.next;
}
p.next = new Node(t, p.next);
N++;
}
public void delete(int i) {
if (i < 1 || i > N) {
throw new RuntimeException("删除位置不正确");
}
Node p = head;
for (int index = 1; index < i; index++) {
p = p.next;
}
p.next = p.next.next;
N--;
}
public void reverse() {
Node p = head;
reverse(p.next);
}
private Node reverse(Node p) {
if (p.next == null) {
head.next = p;
return p;
}
Node per = reverse(p.next);
per.next = p;
p.next = null;
return p;
}
@Override
public Iterator<T> iterator() {
return new Iterator() {
private Node p = head;
@Override
public boolean hasNext() {
return p.next != null;
}
@Override
public Object next() {
p = p.next;
return p.item;
}
};
}
}
测试类代码如下:
package com.apesblog.ReverseLinkList1;
public class Test {
public static void main(String[] args) {
ReverseLinkList1<String> l = new ReverseLinkList1<String>();
l.add("1");
l.add("2");
l.add("3");
l.add("4");
StringBuilder str = new StringBuilder(300);
str.append("遍历:");
for (String s : l) {
str.append(s + " ");
}
System.out.println(str);
l.reverse();
str.delete(0, str.length());
str.append("反转:");
for (String s : l) {
str.append(s + " ");
}
System.out.println(str);
}
}
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