1 files changed, 100 insertions, 0 deletions
diff --git a/0021/src/main.rs b/0021/src/main.rs
new file mode 100644
index 0000000..a53e20c
--- /dev/null
+++ b/0021/src/main.rs
@@ -0,0 +1,100 @@
+#[derive(PartialEq, Eq, Clone, Debug)]
+pub struct ListNode {
+    pub val: i32,
+    pub next: Option<Box<ListNode>>
+}
+//
+impl ListNode {
+    #[inline]
+    pub fn new(val: i32) -> Self {
+        ListNode {
+            next: None,
+            val
+        }
+    }
+}
+
+pub fn vector2list(vec: Vec<i32>) -> Option<Box<ListNode>> {
+    let mut result: Option<Box<ListNode>> = None;
+    for i in 0..vec.len() {
+        let mut new_result = Some(Box::new(ListNode::new(vec[vec.len() - i - 1])));
+        new_result.as_mut().unwrap().next = result;
+        result = new_result;
+    }
+    result
+}
+
+pub fn list2vector(lst: Option<Box<ListNode>>) -> Vec<i32> {
+    let mut result: Vec<i32> = Vec::new();
+    let mut cur = &lst;
+    loop {
+        match cur {
+            None => break,
+            Some(node) => {
+                result.push(node.val);
+                cur = &node.next;
+            },
+        }
+    }
+    result
+}
+
+
+impl Solution {
+    pub fn merge_two_lists(list1: Option<Box<ListNode>>, list2: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        let mut p1 = &list1;
+        let mut p2 = &list2;
+        let mut result: Vec<i32> = vec!();
+        loop {
+            let v1: i32;
+            let v2: i32;
+            match p1 {
+                None => {
+                    match p2 {
+                        None => break,
+                        Some(px) => {
+                            result.push(px.val);
+                            p2 = &px.next;
+                            continue;
+                        }
+                    }
+                },
+                Some(p1) => { v1 = p1.val; },
+            }
+            match p2 {
+                None => {
+                    match p1 {
+                        None => break,
+                        Some(px) => {
+                            result.push(px.val);
+                            p1 = &px.next;
+                            continue;
+                        }
+                    }
+                },
+                Some(p2) => { v2 = p2.val; },
+            }
+            if v1 <= v2 {
+                result.push(v1);
+                p1 = match p1 {
+                    Some(px) => &px.next,
+                    None => p1,
+                };
+            } else {
+                result.push(v2);
+                p2 = match p2 {
+                    Some(px) => &px.next,
+                    None => p2,
+                };
+            }
+        }
+        vector2list(result)
+    }
+}
+
+struct Solution {}
+fn main() {
+    println!("{:?}", list2vector(
+        Solution::merge_two_lists(vector2list(vec!(1,3,5)),
+                                  vector2list(vec!(2,4,6)))));
+}
+\ No newline at end of file