diff --git a/problems/0056.合并区间.md b/problems/0056.合并区间.md
index 72dc69c5..952d32af 100644
--- a/problems/0056.合并区间.md
+++ b/problems/0056.合并区间.md
@@ -312,24 +312,22 @@ object Solution {
 
 ```Rust
 impl Solution {
-    fn max(a: i32, b: i32) -> i32 {
-        if a > b { a } else { b }
-    }
-
-    pub fn merge(intervals: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
-        let mut intervals = intervals;
-        let mut result = Vec::new();
-        if intervals.len() == 0 { return result; }
-        intervals.sort_by(|a, b| a[0].cmp(&b[0]));
-        result.push(intervals[0].clone());
-        for i in 1..intervals.len() {
-            if result.last_mut().unwrap()[1] >= intervals[i][0] {
-                result.last_mut().unwrap()[1] = Self::max(result.last_mut().unwrap()[1], intervals[i][1]);
+    pub fn merge(mut intervals: Vec<Vec<i32>>) -> Vec<Vec<i32>> {
+        let mut res = vec![];
+        if intervals.is_empty() {
+            return res;
+        }
+        intervals.sort_by_key(|a| a[0]);
+        res.push(intervals[0].clone());
+        for interval in intervals.into_iter().skip(1) {
+            let res_last_ele = res.last_mut().unwrap();
+            if res_last_ele[1] >= interval[0] {
+                res_last_ele[1] = interval[1].max(res_last_ele[1]);
             } else {
-                result.push(intervals[i].clone());
+                res.push(interval);
             }
         }
-        result
+        res
     }
 }
 ```