创建输出逆置链表

import 链表问题.ElemSN.ElemNode;

public  class ElemSN {
	//链表节点
	 class ElemNode{
		Integer value;
		ElemNode next;
		public ElemNode() {
		}
	}

	//创建链表
	public  ElemNode createLink(int arr[]) {
		ElemNode head = null;
		ElemNode p = null;
		ElemNode tail = null;
		for (int i = 0; i < arr.length; i++) {
			p = new ElemNode();
			p.value = arr[i];
			p.next = null;
			if(head == null) {
				head = p;
				tail = p;
			}
			tail = tail.next = p;
		}
		return head;
	}
	
	//逆置链表
	public ElemNode inversionLink(ElemNode head){
		ElemNode n1 = head;
		ElemNode n2 = head.next;
		ElemNode n3 = null;
		n1.next = null;
		while(n2 != null) {
			n3 = n2.next;
			n2.next = n1;
			n1 = n2;
			n2 = n3;
		}
		return n1;
		
	}
	
	//输出链表
	public  void printLink(ElemNode head) {
		for(ElemNode p = head; p != null; p = p.next ) {
			System.out.print(p.value+" ");
		}
		System.out.println();
	}
}
class Test {
	public static void main(String[] args) {
		int arr[] = {3,2,5,7,8,9,9};
		ElemSN elemSN =  new ElemSN();
		ElemNode head = null;
		//创建输出链表
		head = elemSN.createLink(arr);
		elemSN.printLink(head);
		//逆置链表
		head = elemSN.inversionLink(head);
		elemSN.printLink(head);
	}
}