leetcode/
remove_elements.rs

1//! # 203. 移除链表元素
2//!
3//! 难度 简单
4//!
5//! 删除链表中等于给定值 val 的所有节点。
6//!
7//! ## 示例:
8//!
9//! ```text
10//! 输入: 1->2->6->3->4->5->6, val = 6
11//! 输出: 1->2->3->4->5
12//! ```
13//!
14//! See [leetcode](https://leetcode-cn.com/problems/remove-linked-list-elements/)
15
16use crate::ListNode;
17
18pub struct Solution;
19
20impl Solution {
21    pub fn remove_elements(head: Option<Box<ListNode>>, val: i32) -> Option<Box<ListNode>> {
22        let mut dummy = Some(Box::new(ListNode{ next: head, val: 0 }));
23        let mut node = &mut dummy;
24        while node.is_some() && node.as_ref().unwrap().next.is_some() {
25            if node.as_ref().unwrap().next.as_ref().unwrap().val == val {
26                let n = node.as_mut().unwrap().next.take();
27                node.as_mut().unwrap().next = n.unwrap().next;
28                continue;
29            }
30            node = &mut node.as_mut().unwrap().next;
31        }
32        dummy.unwrap().next
33    }
34}
35
36#[cfg(test)]
37mod tests {
38    use super::*;
39    use crate::list;
40
41    #[test]
42    fn test() {
43        let cases = vec![
44            (vec![1,2,3,4,5], (list![1,2,6,3,4,5,6], 6)),
45            (vec![], (list![], 6)),
46        ];
47        let t = |v, t| ListNode::into_vec(Solution::remove_elements(v, t));
48        for (expect, (input, val)) in cases {
49            assert_eq!(expect, t(input, val));
50        }
51    }
52}
leetcode/remove_elements.rs

leetcode/
remove_elements.rs
