It seems that assert statements are compiled when I submit a solution to a problem, which hurts the runtime in case complex assertions are used. I would prefer if the assertions were enabled when I "Run Code" but disabled when I "Submit Solution".
Assertions can be disabled by defining the macro NDEBUG before including <cassert>. Details:

• C++ Reference
• Stack Overflow

As a workaround, I redefine the assert macro in the beginning of my code when I want to disable the assertions:

#undef assert
#define assert(x)