template_highest.cpp

// Osman Zakir
// 11 / 10 / 2017
// Bjarne Stroustrup: Programming: Principles and Practice Using C++ 2nd Edition
// Chapter 20 "Find highest element" example code (with templated high() function)
// This program has a serious bug that I have to find and fix.

#include "../../cust_std_lib_facilities.h"
#include <algorithm>
#include <iostream>
#include <fstream>
#include <vector>
#include <vld.h>

template<typename Iterator>
Iterator high(Iterator first, Iterator last);
double *get_from_jack(int *count);
std::vector<double> *get_from_jill();
void fct();

int main()
{
	try
	{
		fct();
	}
	catch (const std::exception &e)
	{
		std::cerr << "Exception: " << e.what() << '\n';
	}
	keep_window_open();
}

template<typename Iterator>
Iterator high(Iterator first, Iterator last)
	// return an iterator to the element in [first:last) that has the highest value
{
	Iterator high = first;
	for (Iterator p = first; p != last; ++p)
	{
		if (*high < *p)
		{
			high = p;
		}
	}
	return high;
}

double *get_from_jack(int *count)
{
	*count = 45;
	double *data_arr = nullptr;
	try
	{
		data_arr = new double[*count];
	}
	catch (const std::bad_alloc &e)
	{
		std::cout << "Bad allocation error: " << e.what() << '\n';
		if (data_arr != nullptr)
		{
			delete[] data_arr;
			data_arr = nullptr;
		}
	}
	catch (const std::bad_array_new_length &e)
	{
		std::cerr << "Bad array new length error: " << e.what() << '\n';
		delete[] data_arr;
		data_arr = nullptr;
	}
	catch (const std::exception &e)
	{
		std::cout << "Exception: " << e.what() << '\n';
		delete[] data_arr;
		data_arr = nullptr;
	}

	std::ifstream ifs{ "velocities1.txt" };
	std::size_t i = 0;
	for (double velocity; ifs >> velocity;)
	{
		data_arr[i] = velocity;
		++i;
		if (i >= *count)
		{
			break;
		}
	}
	return data_arr;
}

std::vector<double> *get_from_jill()
{
	std::vector<double> *data_vec = nullptr;
	try
	{
		data_vec = new std::vector<double>;
	}
	catch (const std::bad_alloc &e)
	{
		std::cerr << "Bad alloction error: " << e.what() << '\n';
		if (data_vec != nullptr)
		{
			delete data_vec;
			data_vec = nullptr;
		}
	}

	std::ifstream ifs{ "velocities2.txt" };
	for (double velocity; ifs >> velocity;)
	{
		data_vec->push_back(velocity);
	}
	return data_vec;
}

void fct()
{
	int jack_count = 0;
	double *jack_data = get_from_jack(&jack_count);
	std::vector<double> *jill_data = get_from_jill();

	std::sort(jack_data, jack_data + jack_count);
	std::sort(&jill_data->begin(), &jill_data->end());

	double *jack_high = high(jack_data, jack_data + jack_count);
	std::vector<double> &v = *jill_data;
	double *jill_high = high(&v[0], &v[0] + v.size());

	std::cout << "Jill's high " << *jill_high << "; Jack's high " << *jack_high << '\n';

	if (jack_data != nullptr)
	{
		delete[] jack_data;
		jack_data = nullptr;
	}
	if (jill_data != nullptr)
	{
		delete jill_data;
		jill_data = nullptr;
	}
}