How to make this into separate functions and how to extract from a file.

[thisguyluis]

I have this code and I have to do two things. One id to get the numbers from a file that has already been made. Two is to make each problem into a function. Such as a function for getting the minimum number and a function to get the highest number. If I could get help with at least the one to make each one a function, I will be very thankful.

#include<iostream>
using namespace std;
int main()
{
	int arr[10], n, i, max, min;
	cout << "Enter the size of the array : ";
	cin >> n;
	cout << "Enter the elements of the array : ";
	for (i = 0; i < n; i++)
		cin >> arr[i];
	max = arr[0];
	for (i = 0; i < n; i++)
	{
		if (max < arr[i])
			max = arr[i];
	}
	min = arr[0];
	for (i = 0; i < n; i++)
	{
		if (min > arr[i])
			min = arr[i];
	}
	cout << "Largest element : " << max;
	cout << " Smallest element : " << min;

	cout << "\n\n";
	system("pause");
	return 0;
}

Thank you for your time.

[JLBorges]

#include <iostream>
#include <vector>
#include <fstream>
#include <climits>

// get the numbers from a file that has already been made.
// vector: https://cal-linux.com/tutorials/vectors.html
std::vector<int> get_numbers_from( std::istream& file )
{
    std::vector<int> array ;

    int number ;

    while( file >> number ) // for each number read from the input stream
        array.push_back(number) ; // add it to the array

    return array ;
}

int smallest_number_in( const std::vector<int>& numbers )
{
    int min_value = INT_MAX ; // http://www.cplusplus.com/reference/climits/

    // range based loop: http://www.stroustrup.com/C++11FAQ.html#for
    for( int value : numbers ) if( value < min_value ) min_value = value ;

    return min_value ;
}

int largest_number_in( const std::vector<int>& numbers )
{
    int max_value = INT_MIN ; // http://www.cplusplus.com/reference/climits/
    for( int value : numbers ) if( value > max_value ) max_value = value ;
    return max_value ;
}

void process_file( const char file_name[]  )
{
    if( std::ifstream file{file_name} ) // if the file was successfully opened
    {
        const std::vector<int> numbers = get_numbers_from(file) ;

        if( !numbers.empty() ) // if at least one number was read from the file
        {
            std::cout << numbers.size() << " numbers were read\n"
                      << "smallest: " << smallest_number_in(numbers) << '\n'
                      << "largest: " << largest_number_in(numbers) << '\n' ;
        }

        else std::cout << "no numbers were read from the file\n" ;
    }

    else std::cout << "failed to open file " << file_name << " for input\n" ;
}

int main()
{
    const char file_name[] = "numbers.txt" ;
    process_file(file_name) ;
}