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//Get data file at https://codecatch.net/post.php?postID=91e87d73
//Iteration 1 of Wing Project. Solution breaks down around n=35

#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <map>
using namespace std;

int getSum(map<int, int> list);
void readData(map<int, float>* data);
void lowestPrice();
void findSums(int n, vector<map<int, int>>* sumsList, map<int, float>* data);
//void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList);
void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList, map<int, float>* data);
float getPrice(map<int, int> set, map<int, float>* data);

template <typename S>
ostream& operator<<(ostream& os, const vector<S>& vector)
{
	// Printing all the elements using <<
	for (auto element : vector) {
	os << element << " ";
	}
	return os;
}

bool operator==(map<int, int> m1, map<int, int> m2)
{
	if(m1.size() != m2.size())
	return false;

	bool ret = true;

	for(auto it = m1.begin(); it !=m1.end() && ret; it++)
	{
	if(ret && m1.count(it->first) != m2.count(it->first))
	ret = false;

	if(ret && m1.count(it->first) == 1)
	{
	if(m1.at(it->first) != m2.at(it->first))
	ret = false;
	}
	}

	return ret;
}


int main()
{
	map<int, float> data;
	readData(&data);

	vector<map<int, int>> *sumsList;
	sumsList = new vector<map<int, int>>;
	findSums(40, sumsList, &data);

	for(auto el : *sumsList)
	{
	for(auto it = el.begin(); it != el.end(); it++)
	{
	cout << it->first << "->" << it->second << " ";
	}
	cout << getPrice(el, &data) << endl;
	}

	return 0;
}

/* Returns the price of wings given a set of numbers of wings to buy.
	* Returns -1 if the set contains a number that is not possible to buy.
	*/
float getPrice(map<int, int> set, map<int, float>* data)
{
	float price = 0;
	for(auto it = set.begin(); it != set.end(); it++)
	{
	//If data doesn't contain an element of set, return -1
	if(data->count(it->first) == 0)
	return -1;
	
	price += data->at(it->first) * it->second; //pricePerPacket * qtyOfPackets
	}

	return price;
}

/* Adds the elements of list.
	* Suppose mapping is <num, qty>.
	* Returns sum(num*qty)
	*/
int getSum(map<int, int> list)
{
	int sum = 0;
	for(auto it = list.begin(); it != list.end(); it++)
	sum += it->first * it->second;
	return sum;
}

void findSums(int n, vector<map<int, int>>* sumsList, map<int, float>* data)
{
	map<int, int> currList;

	//Recur when currSum < n
	auto it = data->begin();
	while(it->first <= n && it != data->end())
	{
	findSum(currList, it->first, n, sumsList, data);
	it++;
	}
}

void findSum(map<int, int> currList, int x, int n, vector<map<int, int>>* sumsList, map<int, float>* data)
{
	//Append x to currList
	if(currList.count(x) == 0)
	currList.emplace(x, 1);
	else
	{
	int val = 1+ currList.at(x);
	currList.erase(x);
	currList.emplace(x, val);
	}

	//Determine current sum, check for return cases
	int currSum = getSum(currList);

	if(currSum > n)
	return;
	else if(currSum == n)
	{

	//Check to make sure no duplicates
	for(auto list : *sumsList)
	{
	if(list == currList)
	return;
	}

	sumsList->push_back(currList);
	return;
	}

	//Recur when currSum < n
	auto it = data->begin();
	while(it->first <= n-x && it != data->end())
	{
	findSum(currList, it->first, n, sumsList, data);
	it++;
	}
}

void readData(map<int, float>* data)
{
	ifstream file ("./data", ifstream::in);

	if(file.is_open())
	{
	int i = 0;
	while(!file.eof())
	{
	float wings, price;
	string skipnl;
	file >> wings;
	file >> price;

	data->emplace(wings, price);

	getline(file, skipnl);
	i++;
	}
	}
}