Merge Sort concern

[NirBoneh]

For the merge sort did you mean for it to be a function of type int vector instead of void, because in the pdf example you sent us you have code that shows:
left_list = mergesort(left_list)
right_list = mergesort(right_list)
which is simply not possible when the merge sort function is a void.

Edit:
Found out that merge sort is possible with the mergesort function being of type void pay no attention to this.

[AThilenius]

It C++ it is very possible, and very common for a function to return void but perform an action on it's parameters. Hence the pointer type :) Although if I remember correctly, even a pointer type is not needed to achieve the same thing. You could pass the vector by value, change it, and the changes would stick. Still, the pointer makes it very clear what is going on.

[NirBoneh]

Yeah I figured it out I just felt like the pdf file was a little confusing since it showed code that couldn't be used in the actual code.