#include<iostream>
using std::cout; using std::endl; using std::cin;
#include<fstream>
using std::ifstream;
#include<string>
using std::string;
#include<algorithm>
using std::copy; using std::copy_if; using std::swap;
#include<fstream>
using std::ifstream;
#include<utility>
using std::pair; using std::make_pair;

#include "lab11_arrays.h"

/*
Alex Ralya Lab 11
*/

template<typename T>
void insert(T* (&ary), size_t &sz, size_t indx, T val){
  if (indx >= sz){
    sz = indx+1;
    T* new_ary = new T[sz]{};
    copy(ary, ary+sz, new_ary);
    swap(ary,new_ary);
    delete [] new_ary;
  }
  ary[indx] = val;
}

size_t fill_from_file(long*& array, string fileName) {

    ifstream in_file(fileName);

    if (in_file){

        string line;
        int counter = 0;
        size_t sz = 0;

        while(std::getline(in_file,line)) {
          if(counter == 0) {
              array = new long[std::stol(line)]
              counter++
          } else {
              sz++;
              insert(array, sz, (counter-1), std::stol(line));
          }
        }

        return sz;

    } else {
    throw std::runtime_error("File could not be opened!");
    }

}

void print_array(long* array[], size_t sizeOfArray, ostream& oss) {

    for(int i=0; i < sizeOfArray; i++) {
        oss << array[i] << " ";
    }

    cout << oss.str();

}

size_t concatenate(long*& array1, size_t &sizeOfArray1, long* array2, size_t sizeOfArray2) {

    int *array1Front = array1;
    int *array1Back = array1 + sizeOfArray1;

    sizeOfArray1 = sizeOfArray1 + sizeOfArray2;
    int *newArray = new long[sizeOfArray1 + sizeOfArray2]{};
    copy(array1, array1+sizeOfArray1, newArray);
    copy(array2, array2 + sizeOfArray2, newArray + sizeOfArray1);
    swap(array1, newArray);
    delete [] newArray;

    return sizeOfArray1;

}

pair<long*, size_t> copy_evens(long array[], size_t sz) {

    size_t szForNewArray = 0;

    for(auto element: array) {

        if(element%2==0){
            szForNewArray++;
        }

    }

    int *newArray = new long[szForNewArray]{};

    copy_if(array, array + sz, newArray, [](long i) {
        return !(i%2);
    } );

    pair<long*, size_t> thePair[newArray, szForNewArray];
    return thePair;

}