diff --git a/codes/cpp/chapter_computational_complexity/iteration.cpp b/codes/cpp/chapter_computational_complexity/iteration.cpp
index 16d9e1e0f..f17a27e85 100644
--- a/codes/cpp/chapter_computational_complexity/iteration.cpp
+++ b/codes/cpp/chapter_computational_complexity/iteration.cpp
@@ -23,7 +23,7 @@ int whileLoop(int n) {
     // 循环求和 1, 2, ..., n-1, n
     while (i <= n) {
         res += i;
-        i += 1; // 更新条件变量
+        i++; // 更新条件变量
     }
     return res;
 }
@@ -32,12 +32,12 @@ int whileLoop(int n) {
 int whileLoopII(int n) {
     int res = 0;
     int i = 1; // 初始化条件变量
-    // 循环求和 1, 2, 4, 5...
+    // 循环求和 1, 4, ...
     while (i <= n) {
         res += i;
-        i += 1; // 更新条件变量
-        res += i;
-        i *= 2; // 更新条件变量
+        // 更新条件变量
+        i++;
+        i *= 2;
     }
     return res;
 }
diff --git a/codes/java/chapter_computational_complexity/iteration.java b/codes/java/chapter_computational_complexity/iteration.java
index 4f1293fca..fd628db14 100644
--- a/codes/java/chapter_computational_complexity/iteration.java
+++ b/codes/java/chapter_computational_complexity/iteration.java
@@ -24,7 +24,7 @@ public class iteration {
         // 循环求和 1, 2, ..., n-1, n
         while (i <= n) {
             res += i;
-            i += 1; // 更新条件变量
+            i++; // 更新条件变量
         }
         return res;
     }
@@ -33,12 +33,12 @@ public class iteration {
     public static int whileLoopII(int n) {
         int res = 0;
         int i = 1; // 初始化条件变量
-        // 循环求和 1, 2, 4, 5...
+        // 循环求和 1, 4, ...
         while (i <= n) {
             res += i;
-            i += 1; // 更新条件变量
-            res += i;
-            i *= 2; // 更新条件变量
+            // 更新条件变量
+            i++;
+            i *= 2;
         }
         return res;
     }
diff --git a/codes/python/chapter_computational_complexity/iteration.py b/codes/python/chapter_computational_complexity/iteration.py
index 596a9960d..2f8339841 100644
--- a/codes/python/chapter_computational_complexity/iteration.py
+++ b/codes/python/chapter_computational_complexity/iteration.py
@@ -29,12 +29,12 @@ def while_loop_ii(n: int) -> int:
     """while 循环（两次更新）"""
     res = 0
     i = 1  # 初始化条件变量
-    # 循环求和 1, 2, 4, 5...
+    # 循环求和 1, 4, ...
     while i <= n:
         res += i
-        i += 1  # 更新条件变量
-        res += i
-        i *= 2  # 更新条件变量
+        # 更新条件变量
+        i += 1
+        i *= 2
     return res
 
 
diff --git a/mkdocs.yml b/mkdocs.yml
index 1e4ad5f52..c92d8f3d9 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -148,6 +148,7 @@ nav:
     # [icon: material/timer-sand]
     - chapter_computational_complexity/index.md
     - 2.1 &nbsp; 算法效率评估: chapter_computational_complexity/performance_evaluation.md
+    # [status: new]
     - 2.2 &nbsp; 迭代与递归: chapter_computational_complexity/iteration_and_recursion.md
     - 2.3 &nbsp; 时间复杂度: chapter_computational_complexity/time_complexity.md
     - 2.4 &nbsp; 空间复杂度: chapter_computational_complexity/space_complexity.md