leetcode: Add remove duplicates from sorted list

leetcode/0083.remove-duplicates-from-sorted-list/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "lc-0083-remove-duplicates-from-sorted-list"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]

leetcode/0083.remove-duplicates-from-sorted-list/src/main.rs

@@ -0,0 +1,80 @@
+// 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)]
+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 item in slice.iter().rev() {
+            list = Self::cat(list, *item);
+        }
+        list
+    }
+
+    pub fn cat(list: Option<Box<Self>>, val: i32) -> Option<Box<Self>> {
+        Some(Box::new(Self { val, next: list }))
+    }
+}
+
+fn solution1(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+    if let Some(head) = head {
+        let val = head.val;
+        if let Some(next) = head.next {
+            if next.val == val {
+                ListNode::cat(solution1(next.next), val)
+            } else {
+                ListNode::cat(solution1(Some(next)), val)
+            }
+        } else {
+            Some(head)
+        }
+    } else {
+        None
+    }
+}
+
+fn main() {
+    let list = ListNode::from_slice(&[1, 1, 2]);
+    let result = solution1(list);
+    println!("result: {result:?}");
+    let expected_result = ListNode::from_slice(&[1, 2]);
+    assert_eq!(result, expected_result);
+
+    let list = ListNode::from_slice(&[1, 1, 2, 3, 3]);
+    let result = solution1(list);
+    println!("result: {result:?}");
+    let expected_result = ListNode::from_slice(&[1, 2, 3]);
+    assert_eq!(result, expected_result);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{solution1, ListNode};
+
+    #[test]
+    fn test_solution1() {
+        let list = ListNode::from_slice(&[1, 1, 2]);
+        let result = solution1(list);
+        let expected_result = ListNode::from_slice(&[1, 2]);
+        assert_eq!(result, expected_result);
+
+        let list = ListNode::from_slice(&[1, 1, 2, 3, 3]);
+        let result = solution1(list);
+        let expected_result = ListNode::from_slice(&[1, 2, 3]);
+        assert_eq!(result, expected_result);
+    }
+}