//* Introduction to the concept of iterator (pointer alike data structure) *
#include <cstddef>
#include<iostream>
#include<vector>
using namespace std;


int main() {
    vector<double> V;
    size_t n;
    cout << "Please enter the number of elements for the vector" << endl;
    cin >> n;
    V.resize(n);
    cout << "Please enter the values for the vector one by one:" << endl;
    size_t i;
    for (i=0; i<V.size(); i++)
        cin >> V[i];


    // classic array style access
    for (i=0; i<V.size(); i++)
        cout << " " << V[i];
    cout << endl;

    // sequential pointer-alike access with iterators
    vector<double>::iterator it;
    for (it=V.begin(); it!=V.end(); ++it)
        cout << " " << *it;
    cout << endl;

    // V.begin() - inline FN that returns memory location of the first vector element
    // *V.begin() is equivalent to V.front()
    // V.end()   - inline FN that returns memory location of one AFTER the last used vector element
    // *V.end() IS NOT equivalent to V.back(), in fact *V.end() must not be used at all

    // what about constant arrays? (this one was not constant)
    vector<double>::const_iterator cit;
    for (cit=V.begin(); cit!=V.end(); ++cit)
        cout << " " << *cit;
    cout << endl;

    // reverse? - what's that?
    vector<double>::reverse_iterator rit;
    for (rit=V.rbegin(); rit!=V.rend(); ++rit)
        cout << " " << *rit;
    cout << endl;

    // const_reverse_? - oh, yes! It does exist
    // ... left for your own experimentation ...
    
    return(0);
}