Defining vector size

[Naomi32]

I cannot work out how I can create a vector such, that the user has to enter the length of that vector...

Thanks for helping!

[Repentinus]

Ask the size from a user, store it in variable n and then do vector <whatEverTypeYouNeed> yourVectorName(n);

[Bazzy]

Use the resize function http://www.cplusplus.com/reference/stl/vector/resize.html