setup link list

leetcode/src/list.rs

@@ -1,13 +1,95 @@
 // Definition for singly-linked list.
 #[derive(PartialEq, Eq, Clone, Debug)]
-pub struct ListNode {
-    pub val: i32,
-    pub next: Option<Box<ListNode>>,
+pub struct ListNode<T: PartialEq + Eq> {
+    pub val: T,
+    pub next: Option<Box<ListNode<T>>>,
 }
 
-impl ListNode {
+impl<T: PartialEq + Eq> ListNode<T> {
     #[inline]
-    fn new(val: i32) -> Self {
+    fn new(val: T) -> Self {
         ListNode { next: None, val }
     }
+
+    pub fn create_list<const N: usize>(v: [T; N]) -> Option<Box<Self>> {
+        let mut head = None;
+
+        for item in v.into_iter().rev() {
+            head = Some(Box::new(ListNode {
+                val: item,
+                next: head,
+            }));
+        }
+
+        head
+    }
+}
+
+pub fn assert_eq_list<T: PartialEq + Eq>(
+    l1: &Option<Box<ListNode<T>>>,
+    l2: &Option<Box<ListNode<T>>>,
+) -> bool {
+    let mut p1 = l1;
+    let mut p2 = l2;
+    while let (Some(node1), Some(node2)) = (p1, p2) {
+        if node1.val != node2.val {
+            return false;
+        }
+        p1 = &node1.next;
+        p2 = &node2.next;
+    }
+
+    p1.is_none() && p2.is_none()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_create_list() {
+        let v = [1, 3, 2];
+        let list = ListNode::create_list(v.clone());
+
+        let mut head = &list;
+        let mut v = Vec::from(v);
+        while let Some(node) = head {
+            let item = v.remove(0);
+            assert_eq!(item, node.val);
+            head = &node.next;
+        }
+    }
+
+    #[test]
+    fn test_assert_eq_list() {
+        let l1 = Some(Box::new(ListNode {
+            val: 0,
+            next: Some(Box::new(ListNode {
+                val: 1,
+                next: Some(Box::new(ListNode { val: 2, next: None })),
+            })),
+        }));
+        let l2 = Some(Box::new(ListNode {
+            val: 0,
+            next: Some(Box::new(ListNode {
+                val: 1,
+                next: Some(Box::new(ListNode { val: 2, next: None })),
+            })),
+        }));
+        let l3 = Some(Box::new(ListNode {
+            val: 0,
+            next: Some(Box::new(ListNode {
+                val: 1,
+                next: Some(Box::new(ListNode { val: 3, next: None })),
+            })),
+        }));
+        let l4 = Some(Box::new(ListNode {
+            val: 0,
+            next: Some(Box::new(ListNode { val: 1, next: None })),
+        }));
+
+        assert!(assert_eq_list(&l1, &l2));
+        assert!(!assert_eq_list(&l1, &l3));
+        assert!(!assert_eq_list(&l1, &l4));
+    }
 }

leetcode/src/solutions.rs

@@ -1,5 +1,6 @@
 use anyhow::Result;
 
+pub mod add_two_numbers;
 pub mod two_sum;
 
 pub trait Solution: Send + Sync {

leetcode/src/solutions/add_two_numbers.rs

@@ -0,0 +1,54 @@
+use super::Solution;
+use crate::list::{assert_eq_list, ListNode};
+
+pub struct AddTwoNumbers;
+
+impl Solution for AddTwoNumbers {
+    fn name(&self) -> String {
+        "Add Two Numbers Solution".into()
+    }
+    fn problem_id(&self) -> usize {
+        2
+    }
+    fn test(&self) -> anyhow::Result<()> {
+        let testcases = [
+            (
+                ListNode::create_list([2, 4, 3]),
+                ListNode::create_list([5, 6, 4]),
+                ListNode::create_list([7, 0, 8]),
+            ),
+            (
+                ListNode::create_list([0]),
+                ListNode::create_list([0]),
+                ListNode::create_list([0]),
+            ),
+            (
+                ListNode::create_list([9, 9, 9, 9, 9, 9, 9]),
+                ListNode::create_list([9, 9, 9, 9]),
+                ListNode::create_list([8, 9, 9, 9, 0, 0, 0, 1]),
+            ),
+        ];
+
+        for (l1, l2, expect) in testcases {
+            let output = Self::add_two_numbers(l1, l2);
+
+            if !assert_eq_list(&expect, &output) {
+                // TODO: print link list
+                anyhow::bail!("test failed in AddTwoNumbers solution");
+            }
+        }
+        Ok(())
+    }
+    fn benchmark(&self) -> anyhow::Result<usize> {
+        anyhow::bail!("TODO");
+    }
+}
+
+impl AddTwoNumbers {
+    pub fn add_two_numbers(
+        l1: Option<Box<ListNode<i32>>>,
+        l2: Option<Box<ListNode<i32>>>,
+    ) -> Option<Box<ListNode<i32>>> {
+        todo!()
+    }
+}