/*
Good morning! Here's your coding interview problem for today.

This problem was asked by Stripe.

Given an array of integers, find the first missing positive integer in linear time and constant space. In other words, find the lowest positive integer that does not exist in the array. The array can contain duplicates and negative numbers as well.

For example, the input [3, 4, -1, 1] should give 2. The input [1, 2, 0] should give 3.

You can modify the input array in-place.
*/
#include <iostream>
using namespace std;

int calcMissing(int* input, int size)
{
	int sum = 0;
	int n = 1; //add one to account for missing value
	for(int i = 0; i < size; i++)
	{
	if(input[i] > 0)
	{
	sum += input[i];
	n++;
	}
	}

	//If no numbers higher than 0, answer is 1
	if(sum == 0)
	return 1;

	return (n*(n+1)/2) - sum; //Formula is expectedSum - actualSum
	/* expectedSum = n*(n+1)/2, the formula for sum(1, n) */
}

int main()
{

	cout << calcMissing(new int[4]{3, 4, -1, 1}, 4) << endl;
	cout << calcMissing(new int[3]{1, 2, 0}, 3) << endl;

	//No positive numbers
	cout << calcMissing(new int[1]{0}, 1) << endl;
}

int main()

#include <iostream>
using namespace std;
int main()
{
    int arr[] = {5, 1, 4, 20, 10, 2, 13, 11, 6, 21};
    int greed[] = {0, 0, 0, 0};
    int k = 0;
    int i;
    int set_index;
    while (k < 4)
    {
        i = 0;
        while (i < 10)
        {
            if (arr[i] > greed[k])
            {
                greed[k] = arr[i];
                set_index = i;
            }
            i++;
        }
        arr[set_index] = 0;
        k++;
    }
    cout << greed[0] << " " << greed[1] << " " << greed[2] << " " << greed[3] << endl;
}

//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++;
	}
	}
}

#include <iostream>
using namespace std;

/* Function: get_coeff
Parameters: double& coeff, int pos passed from bb_4ac
Return: type is void so no return, but does ask for user to input data that establishes what a b and c are.
*/
void get_coeff(double& coeff, int pos) {
  char position;
  if(pos == 1) {
    position = 'a';
  } else if(pos == 2) {   //a simple system to determine what coefficient the program is asking for.
    position = 'b';
  } else {
    position = 'c';
  }
  cout << "Enter the co-efficient " << position << ":"; //prompt to input coeff
  coeff = 5; //input coeff
}

/* Function: bb_4ac
Parameters: no parameters passed from main, but 3 params established in function, double a, b, c.
Return: b * b - 4 * a * c
*/
double bb_4ac() {
  double a, b, c; //coefficients of a quadratic equation
  get_coeff(a, 1); // call function 1st time
  get_coeff(b, 2); // call function 2nd time
  get_coeff(c, 3); // call function 3rd time
  return b * b - 4 * a * c; //return b * b - 4 * a * c
}

int main() {
  cout << "Function to calculate the discriminant of the equation. . . " << endl;
  double determinate = bb_4ac(); //assign double determinate to bb_4ac function
  cout << "The discriminant for given values is: " << determinate << endl;  //output the determinate!
}

#include <iostream>
using namespace std;

int main() {


    int arr[5];
    
    for(int i = 0; i < 5; i++) {
        arr[i] = i;
    }

    for(int i = 0; i < 5; i++) {
        cout << "Outputting array info at position " << i + 1 << ": " << arr[i] << endl;
    }

    for(int i=0;i<5;i++)
	{		
		for(int j=i+1;j<5;j++)
		{
			if(arr[i]>arr[j])
			{
				int temp=arr[i];
				arr[i]=arr[j];
				arr[j]=temp;
			}
		}
	}

    cout << endl;

    for(int i = 0; i < 5; i++) {
        cout << "Outputting sorted array info at position " << i + 1 << ": " << arr[i] << endl;
    }

    return 0;
}