剑指offer-问题5

package offer;

import java.util.Stack;

/**
 * offer interview 05
 */
public class Test05 {
    public static class ListNode{
        int val;
        ListNode next;

        public ListNode(){

        }

        public ListNode(int val){
            this.val = val;
        }
    }

    /**
     * method 1
     * @param root
     */
    public static void printListInverselyUsingIteration(ListNode root){
        Stack<ListNode> stack = new Stack<>();
        while (root != null){
            stack.push(root);
            root = root.next;
        }

        ListNode tmp;

        while (!stack.isEmpty()){
            tmp = stack.pop();
            System.out.print(tmp.val + " ");
        }
        System.out.println();
    }

    /**
     * method 2
     * @param root
     */
    public static void printListInverselyUsingRecursion(ListNode root){
       if (root != null){
           printListInverselyUsingRecursion(root.next);
           System.out.print(root.val + " ");
       }
    }



    public static void main(String[] args){
        ListNode root = new ListNode(1);
        root.next = new ListNode(2);;
        root.next.next = new ListNode(3);
        root.next.next.next = new ListNode(4);
        root.next.next.next.next = new ListNode(5);

        printListInverselyUsingIteration(root);
        System.out.println("==========");
        printListInverselyUsingRecursion(root);

    }



}