题解 | #从尾到头打印链表# | Rust

/**
 *  #[derive(PartialEq, Eq, Debug, Clone)]
 *  pub struct ListNode {
 *      pub val: i32,
 *      pub next: Option<Box<ListNode>>
 *  }
 * 
 *  impl ListNode {
 *      #[inline]
 *      fn new(val: i32) -> Self {
 *          ListNode {
 *              val: val,
 *              next: None,
 *          }
 *      }
 *  }
 */

struct Solution{

}

impl Solution {
    fn new() -> Self {
        Solution{}
    }

    /**
    * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
    * 
        * @param head ListNode类 
        * @return int整型一维数组
    */
    pub fn printListFromTailToHead(&self, head: Option<Box<ListNode>>) -> Vec<i32> {
        if head.is_none() {
            return vec![];
        }
        let mut ans = Vec::new();
        let mut head = head;
        ans.append(&mut Solution::printListFromTailToHead(self, head.as_mut().unwrap().next.take()));
        ans.push(head.as_ref().unwrap().val);
        return ans;
    }
}