I am new to leetcode and I am attempting questions in C++. I have seen that there is a difference in the runtime results and the memory used results between submitting the same results twice. I would like to know if this is normal for every language and are the reults that we are getting reliable.
If not, could someone please guide me about some resources that are reliable in terms of runtime and memory results in the case of C++?

Thank you, I would really appreciate any help on this issue.