題目描述
輸入一個鏈表,從尾到頭打印鏈表每個節點的值
編程思路
程序代碼(Java語言)
import java.util.ArrayList;
class ListNode {
int val;
ListNode next = null;
ListNode(int val) {
this.val = val;
}
}
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;
}
}
2.用棧實現
import java.util.ArrayList;
import java.util.Stack;
class ListNode {
int val;
ListNode next = null;
ListNode(int val) {
this.val = val;
}
}
public class Solution {
public ArrayList<Integer> printListFromTailToHead(ListNode listNode) {
Stack<Integer> stack = new Stack<Integer>();
while(listNode != null) {
stack.push(listNode.val);
listNode = listNode.next;
}
ArrayList<Integer> arraylist = new ArrayList<Integer>();
while(!stack.isEmpty()) {
arraylist.add(stack.pop());
}
return arraylist;
}
}