Compiler error on array declaration?

Question

How do I go about fixing these three errors?

• error C2057: expected constant expression
• error C2466: cannot allocate an array of constant size 0
• e

Answer 1

error C2057: expected constant expression

You can't declare randomTickets like that because the dimensions of the array need to be known at compile time. tickets is not a compile time constant and therefore you have the error. Consider using std::vector<T>:

std::vector<std::vector<int>> randomTickets(tickets, std::vector<int>(SIZE));

Alternatively, you can nest a std::array since SIZE is constant and known at compile time:

std::vector<std::array<int, SIZE>> randomTickets(tickets);

The other errors are resolved by fixing this one.

Answer 2

Variable tickets is not a constant expression, that's why.

Change int randomTickets[tickets][SIZE] as follows:

Array* randomTickets = new Array[tickets];

Outside of function main, declare the following type:

typedef int Array[SIZE];

You can use variable randomTickets as a "normal" 2-dimensional array from this point onwards, just don't forget to delete[] randomTickets when you're done...