leetcode: Add 0082

src/SUMMARY.md

@@ -118,6 +118,7 @@
         - [0075. 颜色分类 Sort Colors](leetcode/0075.sort-colors/index.md)
         - [0078. 子集 Subsets](leetcode/0078.subsets/index.md)
         - [0080. 删除排序数组中的重复项 II Remove Duplicates from Sorted Array II](leetcode/0080.remove-duplicates-from-sorted-array-ii/index.md)
+        - [0082. 删除排序链表中的重复元素 II Remove Duplicates from Sorted List II](leetcode/0082.remove-duplicates-from-sorted-list-ii/index.md)
         - [0083. 删除排序链表中的重复元素 Remove Duplicates from Sorted List](leetcode/0083.remove-duplicates-from-sorted-list/index.md)
         - [0088. 合并两个有序数组 Merge Sorted Array](leetcode/0088.merge-sorted-array/index.md)
         - [0090. 子集 II Subsets II](leetcode/0090.subsets-ii/index.md)

src/leetcode/0082.remove-duplicates-from-sorted-list-ii/index.md

@@ -0,0 +1,3 @@
+# 0082. 删除排序链表中的重复元素 II Remove Duplicates from Sorted List II
+
+[问题描述](../problems/0082.remove-duplicates-from-sorted-list-ii/content.html)

src/leetcode/0082.remove-duplicates-from-sorted-list-ii/src/main.rs

@@ -0,0 +1,139 @@
+// Copyright (c) 2023 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by General Public License that can be
+// found in the LICENSE file.
+
+#![allow(dead_code)]
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ListNode {
+    pub val: i32,
+    pub next: Option<Box<ListNode>>,
+}
+
+impl ListNode {
+    #[inline]
+    #[must_use]
+    pub const fn new(val: i32) -> Self {
+        Self { val, next: None }
+    }
+
+    pub fn from_slice(slice: &[i32]) -> Option<Box<Self>> {
+        let mut list = None;
+        for &val in slice.iter().rev() {
+            list = Some(Box::new(Self { val, next: list }));
+        }
+        list
+    }
+
+    pub fn debug_print(head: &Option<Box<Self>>) {
+        print!("head: [");
+        let mut node_ref = head;
+        while node_ref.is_some() {
+            print!("{}, ", node_ref.as_ref().unwrap().val);
+            node_ref = &node_ref.as_ref().unwrap().next;
+        }
+        println!("]");
+    }
+
+    pub fn debug_print2(head: &Option<Box<Self>>) -> Option<Box<Self>> {
+        print!("head: [");
+        if head.is_some() {
+            let mut node_ref: &ListNode = head.as_ref()?;
+            print!("{}, ", node_ref.val);
+            while let Some(next_ref) = node_ref.next.as_ref() {
+                print!("{}, ", next_ref.val);
+                node_ref = node_ref.next.as_ref()?;
+            }
+        }
+        println!("]");
+        None
+    }
+}
+
+pub fn delete_duplicates1(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+    if head.is_none() {
+        return head;
+    }
+
+    // dummy_head 的下一个节点是 head.
+    // 当 head 及其后面的节点是重复数值时, 这样设计就可以简化处理.
+    // 因为最终返回的, 是 dummy_head->next
+    let mut dummy_head = Some(Box::new(ListNode {
+        val: i32::MIN,
+        next: head,
+    }));
+
+    // 这里, 不再创建 prev 节点, current 节点就当作 prev 节点使用.
+    // 这样为了方便移除后面的节点.
+    let mut current: &mut ListNode = dummy_head.as_mut()?;
+
+    loop {
+        if let Some(next_ref) = current.next.as_mut() {
+            // current->next.val == current->next->next.val
+            if let Some(next_next_ref) = next_ref.next.as_mut() {
+                if next_ref.val == next_next_ref.val {
+                    // 移除所有重复节点
+                    let mut temp: Option<Box<ListNode>> = current.next.take();
+                    // temp.val == temp->next.val
+                    while temp.is_some()
+                        && temp.as_ref()?.next.is_some()
+                        && temp.as_ref()?.val == temp.as_ref()?.next.as_ref()?.val
+                    {
+                        // 这里 temp 指向的当前节点就被 drop 了.
+                        // temp = temp->next;
+                        temp = temp.as_mut()?.next.take();
+                    }
+                    // 将 current 的下一个节点指向 temp 的下一个节点,
+                    // 在下个循环时, 将开始检查它的值.
+                    // current->next = temp->next;
+                    current.next = temp.as_mut()?.next.take();
+                } else {
+                    // 跳到下一个节点
+                    // current = current->next;
+                    current = current.next.as_mut()?;
+                }
+            } else {
+                // 当 current->next->next 为 None 是, 说明 current->next.val 不重复,
+                // 遍历也完成了.
+                break;
+            }
+        } else {
+            // 当 current->next 为 None 是, 说明遍历完成.
+            break;
+        }
+    }
+
+    dummy_head.as_mut()?.next.take()
+}
+
+pub type SolutionFn = fn(Option<Box<ListNode>>) -> Option<Box<ListNode>>;
+
+fn check_solution(func: SolutionFn) {
+    let list = ListNode::from_slice(&[1, 2, 3, 3, 4, 4, 5]);
+    let result = func(list);
+    ListNode::debug_print(&result);
+    //println!("result: {result:?}");
+    let expected_result = ListNode::from_slice(&[1, 2, 5]);
+    assert_eq!(result, expected_result);
+
+    let list = ListNode::from_slice(&[1, 1, 1, 2, 3]);
+    let result = func(list);
+    ListNode::debug_print(&result);
+    //println!("result: {result:?}");
+    let expected_result = ListNode::from_slice(&[2, 3]);
+    assert_eq!(result, expected_result);
+}
+
+fn main() {
+    check_solution(delete_duplicates1);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{check_solution, delete_duplicates1};
+
+    #[test]
+    fn test_solution1() {
+        check_solution(delete_duplicates1);
+    }
+}

src/leetcode/tags/linked-list.md

@@ -13,7 +13,8 @@ TODO:
 
 ## 中等
 
-1. [0707. 设计链表 Design Linked List](../0707.design-linked-list/index.md)
+1. [0082. 删除排序链表中的重复元素 II Remove Duplicates from Sorted List II](../0082.remove-duplicates-from-sorted-list-ii/index.md)
+2. [0707. 设计链表 Design Linked List](../0707.design-linked-list/index.md)
 
 TODO: