feat: add rust solution to lc problem: No.0002

No.0002.Add Two Numbers

Author: YangFong

solution/0000-0099/0002.Add Two Numbers/README.md

@@ -339,6 +339,51 @@ proc addTwoNumbers(l1: var SinglyLinkedList, l2: var SinglyLinkedList): SinglyLi
   result = aggregate
 ```
 
+### **Rust**
+
+```rust
+// Definition for singly-linked list.
+// #[derive(PartialEq, Eq, Clone, Debug)]
+// pub struct ListNode {
+//   pub val: i32,
+//   pub next: Option<Box<ListNode>>
+// }
+//
+// impl ListNode {
+//   #[inline]
+//   fn new(val: i32) -> Self {
+//     ListNode {
+//       next: None,
+//       val
+//     }
+//   }
+// }
+impl Solution {
+    pub fn add_two_numbers(
+        mut l1: Option<Box<ListNode>>,
+        mut l2: Option<Box<ListNode>>,
+    ) -> Option<Box<ListNode>> {
+        let mut dummy = Some(Box::new(ListNode::new(0)));
+        let mut cur = &mut dummy;
+        let mut sum = 0;
+        while l1.is_some() || l2.is_some() || sum != 0 {
+            if let Some(node) = l1 {
+                sum += node.val;
+                l1 = node.next;
+            }
+            if let Some(node) = l2 {
+                sum += node.val;
+                l2 = node.next;
+            }
+            cur.as_mut().unwrap().next = Some(Box::new(ListNode::new(sum % 10)));
+            cur = &mut cur.as_mut().unwrap().next;
+            sum /= 10;
+        }
+        dummy.unwrap().next.take()
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0000-0099/0002.Add Two Numbers/README_EN.md

@@ -327,6 +327,51 @@ proc addTwoNumbers(l1: var SinglyLinkedList, l2: var SinglyLinkedList): SinglyLi
   result = aggregate
 ```
 
+### **Rust**
+
+```rust
+// Definition for singly-linked list.
+// #[derive(PartialEq, Eq, Clone, Debug)]
+// pub struct ListNode {
+//   pub val: i32,
+//   pub next: Option<Box<ListNode>>
+// }
+//
+// impl ListNode {
+//   #[inline]
+//   fn new(val: i32) -> Self {
+//     ListNode {
+//       next: None,
+//       val
+//     }
+//   }
+// }
+impl Solution {
+    pub fn add_two_numbers(
+        mut l1: Option<Box<ListNode>>,
+        mut l2: Option<Box<ListNode>>,
+    ) -> Option<Box<ListNode>> {
+        let mut dummy = Some(Box::new(ListNode::new(0)));
+        let mut cur = &mut dummy;
+        let mut sum = 0;
+        while l1.is_some() || l2.is_some() || sum != 0 {
+            if let Some(node) = l1 {
+                sum += node.val;
+                l1 = node.next;
+            }
+            if let Some(node) = l2 {
+                sum += node.val;
+                l2 = node.next;
+            }
+            cur.as_mut().unwrap().next = Some(Box::new(ListNode::new(sum % 10)));
+            cur = &mut cur.as_mut().unwrap().next;
+            sum /= 10;
+        }
+        dummy.unwrap().next.take()
+    }
+}
+```
+
 ### **...**
 
 ```

solution/0000-0099/0002.Add Two Numbers/Solution.rs

@@ -0,0 +1,40 @@
+// Definition for singly-linked list.
+// #[derive(PartialEq, Eq, Clone, Debug)]
+// pub struct ListNode {
+//   pub val: i32,
+//   pub next: Option<Box<ListNode>>
+// }
+//
+// impl ListNode {
+//   #[inline]
+//   fn new(val: i32) -> Self {
+//     ListNode {
+//       next: None,
+//       val
+//     }
+//   }
+// }
+impl Solution {
+    pub fn add_two_numbers(
+        mut l1: Option<Box<ListNode>>,
+        mut l2: Option<Box<ListNode>>,
+    ) -> Option<Box<ListNode>> {
+        let mut dummy = Some(Box::new(ListNode::new(0)));
+        let mut cur = &mut dummy;
+        let mut sum = 0;
+        while l1.is_some() || l2.is_some() || sum != 0 {
+            if let Some(node) = l1 {
+                sum += node.val;
+                l1 = node.next;
+            }
+            if let Some(node) = l2 {
+                sum += node.val;
+                l2 = node.next;
+            }
+            cur.as_mut().unwrap().next = Some(Box::new(ListNode::new(sum % 10)));
+            cur = &mut cur.as_mut().unwrap().next;
+            sum /= 10;
+        }
+        dummy.unwrap().next.take()
+    }
+}