Rust is fast but it's too fast (multiple times faster than C/C++), so it makes me think if there is something not right.
I get 0 ms runtime. If it's not 0ms it suprises me. The equivalent C++ code will run 12ms in runtime.

It looks like the runtime depends on the number of submissions in the past too.
For example, if you choose the same exact code submitted showing 8ms in C++,
it would now run at 20ms.

Rust example code (0ms)
https://leetcode.com/submissions/detail/201658701

C++ example code (12ms)
https://leetcode.com/submissions/detail/201658891/