diff --git a/README.md b/README.md
index 9790ad137..d0be537da 100644
--- a/README.md
+++ b/README.md
@@ -250,7 +250,7 @@ I'll keep updating for full summary and better solutions. Stay tuned for updates
 735| [Asteroid Collision](https://leetcode.com/problems/asteroid-collision/) | [C++](./C++/asteroid-collision.cpp) [Python](./Python/asteroid-collision.py) | _O(n)_  | _O(n)_         | Medium           ||
 736| [Parse Lisp Expression](https://leetcode.com/problems/parse-lisp-expression/) | [C++](./C++/parse-lisp-expression.cpp) [Python](./Python/parse-lisp-expression.py) | _O(n^2)_  | _O(n^2)_         | Hard           ||
 739| [Daily Temperatures](https://leetcode.com/problems/daily-temperatures/) | [C++](./C++/daily-temperatures.cpp) [Python](./Python/daily-temperatures.py) | _O(n)_  | _O(n)_         | Medium           ||
-770| [Basic Calculator IV](https://leetcode.com/problems/basic-calculator-iv/) | [C++](./C++/basic-calculator-iv.cpp) [Python](./Python/basic-calculator-iv.py) | _O(n)_  | add: _O(d * t)_<br> sub: _O(d * t)_<br> mul: _O(d * t^2)_<br> eval: _O(d * t)_ <br> to_list: _O(d * tlogt)_ | Hard           ||
+770| [Basic Calculator IV](https://leetcode.com/problems/basic-calculator-iv/) | [C++](./C++/basic-calculator-iv.cpp) [Python](./Python/basic-calculator-iv.py) | add: _O(d * t)_<br> sub: _O(d * t)_<br> mul: _O(d * t^2)_<br> eval: _O(d * t)_ <br> to_list: _O(d * tlogt)_  | _O(e + d * t)_ | Hard           ||
 772| [Basic Calculator III](https://leetcode.com/problems/basic-calculator-iii/) | [C++](./C++/basic-calculator-iii.cpp) [Python](./Python/basic-calculator-iii.py) | _O(n)_  | _O(n)_         | Hard           ||
 
 ## Queue