Discussion on Arrays Introduction Challenge

Ethan13310 2 years ago+ 3 comments

We don't want to use C-style array in C++. We use STL containers instead, which have a lot of advantages such as being compatible with STL algorithms, or providing useful member functions such as 'std::vector::size()' (to get the size of the array :D). In this case, we can use 'std::vector', which is a dynamic array. Here's the solution in true C++:

#include <vector>
#include <iostream>
#include <iterator>

int main()
{
    std::size_t size{}; // Here we use 'std::size_t' instead of 'int'
                        // because an array size cannot be negative
    std::cin >> size;
    std::vector<int> vect(size);
    for (std::size_t i{}; i < size; ++i)
    	std::cin >> vect[i];

    // One of the many advantages to use C++ STL containers:
    // we can use reverse iterators
    for (auto rit = vect.rbegin(); rit != vect.rend(); ++rit)
        std::cout << *rit << ' ';
    std::cout << std::endl;
    return 0;
}

Darkling 2 years ago+ 1 comment

Dunno why those but in fact vector is much more heavier than plain array. So there is a good point in using it instead vector. Imho.

Ethan13310 2 years ago+ 2 comments

If you don't want to use std::vector here, you can use std::array instead, not C-style arrays.

And no, std::vector is not 'much more heavier'. It depends on how you use it (i.e. if you do a lot of reallocations). In my code, there is only one allocation since I provide the size at the initialization.