"Algorithm" from tail to head the list Print

0003 list print head from the tail

Title Description

Input a linked list, returns a value from the list according to the order of the tail to the head ArrayList.

Topics address

• https://www.nowcoder.com/practice/d0267f7f55b3412ba93bd35cfa8e8035

Report problem-solving

With the stack output

This problem solution by the micro-channel public number 小猿刷题provided wrong, please correct me.

/**
 *  微信公众号"小猿刷题"
 */
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        Stack<Integer> stack = new Stack<>();
        while(listNode != null){
            stack.push(listNode.val);
            listNode = listNode.next;
        }
        ArrayList<Integer> list = new ArrayList<Integer>();
        while(!stack.isEmpty()){
            list.add(stack.pop());
        }
        return list;
    }
}

With a collection of reversal

This problem solution by the micro-channel public number 小猿刷题provided wrong, please correct me.

/**
 *  微信公众号"小猿刷题"
 */
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> list = new ArrayList<Integer>();
        while(listNode != null){
            list.add(listNode.val);
            listNode = listNode.next;
        }
        Collections.reverse(list);
        return list;
    }
}

With a collection insert

This problem solution by the micro-channel public number 小猿刷题provided wrong, please correct me.

Traverse the list of 0 to traverse each list element into a set of

/**
 *  微信公众号"小猿刷题"
 */
public class Solution {
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        ArrayList<Integer> list = new ArrayList<Integer>();
        while(listNode != null){
            list.add(0, listNode.val);
            listNode = listNode.next;
        }
        return list;
    }
}

Recursive thinking

This problem solution by the micro-channel public number 小猿刷题provided wrong, please correct me.

/**
 *  微信公众号"小猿刷题"
 */
public class Solution {
    ArrayList<Integer> arrayList = new ArrayList<Integer>();
    public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
        if(listNode != null){
            this.printListFromTailToHead(listNode.next);
            arrayList.add(listNode.val);
        }
        return arrayList;
    }
}