I am trying this problem.

Here are two of my submissions: Attempt1 Attempt2

In Attempt1 I am getting runtime error while iterating over vector p, although I am checking it's bounds, while in Attempt2 when I explicitly check if the size of vector p is zero, then there is no runtime error.

I don't think there should be an explicit need to check the size of vector p, as the loop below that won't get executed if it is empty.

Can anyone help out what is the issue?