diff --git a/README.md b/README.md
index d4d88beb..4a554598 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # leetcode
 
-当前已刷：237
+当前已刷：238
 
 ### 题目
 - 1：两数之和
@@ -438,6 +438,9 @@
 - 263：丑数
     - [src](https://github.com/rustors/leetcode/blob/main/src/bin/ugly-number.rs)
     - [leetcode](https://leetcode-cn.com/problems/ugly-number/)
+- 268：丢失的数字
+    - [src](https://github.com/rustors/leetcode/blob/main/src/bin/missing-number.rs)
+    - [leetcode](https://leetcode-cn.com/problems/missing-number/)
 - 290：单词规律
     - [src](https://github.com/rustors/leetcode/blob/main/src/bin/word-pattern.rs)
     - [leetcode](https://leetcode-cn.com/problems/word-pattern/)
diff --git a/src/bin/missing-number.rs b/src/bin/missing-number.rs
new file mode 100644
index 00000000..2fd9b662
--- /dev/null
+++ b/src/bin/missing-number.rs
@@ -0,0 +1,19 @@
+fn main() {
+    println!("{}", Solution::missing_number1(vec![3, 0, 1]));
+    println!("{}", Solution::missing_number1(vec![9, 6, 4, 2, 3, 5, 7, 0, 1]));
+}
+
+struct Solution;
+
+impl Solution {
+    pub fn missing_number(nums: Vec<i32>) -> i32 {
+        (0..=nums.len() as i32).sum::<i32>() - nums.into_iter().sum::<i32>()
+    }
+
+    pub fn missing_number1(nums: Vec<i32>) -> i32 {
+        let l = nums.len() as i32;
+        nums.into_iter().enumerate().fold(l, |l, (x, y)| {
+            x as i32 ^ y ^ l
+        })
+    }
+}