path: root / Year 1 / Programming introduction / Homeworks / homework1.cpp

// 
// ++===================++
// || Оценка: 5.45/6.00 ||
// ++===================++
//
// +-----------+
// | !Бележки! |
// +-----------+
// Трета ти е грешна, не проверяваш правилно (тествай с други числа)  -0.50
// И на първа грешно проверяваш сивото, пробвай с 0 и - 6.5 примерно  -0.05
//

#include <iostream> // cin, cout, endl
#include <cmath>    // fabs, sqrt
#include <stdlib.h> // rand, srand

using namespace std;

/*
 * Exercise 0
 */

/* Floating point arithmetic */

double const FLOAT_EPSILON = 0.001;

bool eq(double a, double b)
{
	return fabs(a - b) < FLOAT_EPSILON;
}

bool lt(double a, double b)
{
	return !eq(a, b) && (a - b) < FLOAT_EPSILON;
}

bool mt(double a, double b)
{
	return lt(b, a);
}

/* Planimetry */

double distanceBetweenPoints(double x1, double y1, double x2, double y2)
{
	double sideA = x1 - x2, sideB = y1 - y2;
	return sqrt(sideA * sideA + sideB * sideB); // Pythagorean theorem
}

void printPointLocation(double x, double y) {
	// The coordinates of points B, C, D and E are some combination of positive and/or negative values of 2.828,
	// because BC and DE make 45 degrees angle with the abscissa
	float const CROSS_PNT = 2.828,
				SLOPE_BC =  CROSS_PNT / CROSS_PNT,
				SLOPE_DE = -CROSS_PNT / CROSS_PNT;
	char const NOWHERE[] = "Nowhere!";

	if (eq(x, 0))
		cout << NOWHERE << endl; // On a line
	else if (lt(distanceBetweenPoints(0, 0, x, y), 4.0))
	{
		double pointSlope = y / x;

		// Added brackets in some places for improved readability
		if (eq(x, -CROSS_PNT) || eq(x, CROSS_PNT) || eq(pointSlope, SLOPE_BC) || (eq(pointSlope, SLOPE_DE) && mt(y, 0)))
		{
			cout << NOWHERE << endl; // On a line
		}
		else if (mt(pointSlope, SLOPE_BC))
		{
			cout << "Inside " << ((x > 0) ? "green" : "blue" ) << " area!" << endl;
		}
		else if (lt(pointSlope, SLOPE_DE) && x < 0)
		{
			cout << "Inside red area!" << endl;
		}
		else if (mt(x, CROSS_PNT))
		{
			cout << "Inside purple area!" << endl;
		}
		else if (mt(x, -CROSS_PNT) && x < 0)
		{
			cout << "Inside pink area!" << endl;
		}
		else if (x > 0)
			cout << "Inside yellow area!" << endl;
		else
			cout << NOWHERE << endl;
	}
	else if (lt(-2, x) && lt(x, 2) && mt(-6, y) && mt(y, -7))
		cout << "Inside grey area!" << endl;
	else
		cout << NOWHERE << endl;
}

/* Exercise calculations */

void ex0()
{
	double x, y;
	cin >> x >> y;

	printPointLocation(x, y);
}

/*
 * Exercise 1
 */

double f(unsigned int k, int x)
{
	unsigned int sum = x;

	for (unsigned int i = 2; i <= k; i++)
	{
		if (sum & 1)
			sum = 3 * sum + 1;
		else
			sum /= 2;
	}

	return sum;
}

void ex1()
{
	int x;
	cin >> x;

	cout << f(35, x) << endl;
}

/*
 * Exercise 2
 */

void setMarmaladeType(unsigned int type, unsigned int* const blueberryMarmalades, unsigned int* const peachMarmalades, unsigned int* const rosehipMarmalades)
{
	if      (type %  7 == 0) *blueberryMarmalades += 1;
	else if (type % 13 == 0) *peachMarmalades     += 1;
	else if (type % 17 == 0) *rosehipMarmalades   += 1;
}

void readCodesAndCountMarmalades(unsigned int archiveLength, unsigned int* const blueberryMarmalades, unsigned int* const peachMarmalades, unsigned int* const rosehipMarmalades)
{
	archiveLength -= archiveLength % 8; // The last code could be invalid (shorter than 8 digits)

	for (unsigned int i = 0, digit, countryDigits, typeDigits, type; i < archiveLength; i++)
	{
		cin >> digit;

		if (i % 8 == 0) // Reset at start of every code
		{
			countryDigits = 1;
			typeDigits = type = 0;
		}
		else if (countryDigits < 3)
		{
			countryDigits++;
		}
		else if (typeDigits < 4)
		{
			typeDigits++;
			type = type * 10 + digit;
		}
		else if (typeDigits == 4)
		{
			setMarmaladeType(type, blueberryMarmalades, peachMarmalades, rosehipMarmalades);
		}
	}
}

void ex2()
{
	unsigned int archiveLength;
	cin >> archiveLength;

	unsigned int blueberryMarmalades = 0, peachMarmalades = 0, rosehipMarmalades = 0;
	readCodesAndCountMarmalades(archiveLength, &blueberryMarmalades, &peachMarmalades, &rosehipMarmalades);
	
	cout << "Blueberry marmalades: " << blueberryMarmalades << endl;
	cout << "Peach marmalades: " << peachMarmalades << endl;
	cout << "Rosehip marmalades: " << rosehipMarmalades << endl;
}

/*
 * Exercise 3
 */

bool isInteresting(int n)
{
	while (n > 9)
	{
		if ((n & 1) == !!(n & 2))
			return false;
		n /= 10;
	}

	return true;
}

int sumOfInterestingNumsBetween(int a, int b)
{
	int sum = 0;

	for (int i = a; i <= b; i++)
	{
		if (isInteresting(i))
			sum += i;
	}

	return sum;
}

void ex3()
{
	int a, b;
	cin >> a >> b;

	cout << sumOfInterestingNumsBetween(a, b) << endl;
}

/* 
 * Exercise 4
 */

const int NUMBER_LENGTH = 4, N = 10;

int genSecretNum()
{
	// Initializes random seed (required for getting a random number on every program launch)
	// Taken from included reference: https://www.cplusplus.com/reference/cstdlib/rand#example
	srand(time(NULL));

	int rnd = rand(), result = 0;
	bool takenDigits[10] = { 0 };
	takenDigits[0] = true; // we can't have 0s in secret

	for (int i = 0; i < NUMBER_LENGTH; i++)
	{
		while (takenDigits[rnd % 10])
		{
			rnd /= 10;
			if (rnd == 0)
				rnd = rand();
		}
		result = result * 10 + rnd % 10;
		takenDigits[rnd % 10] = true;
	}

	return result;
}

bool digitInsideNum(int digit, int num)
{
	while (num != 0)
	{
		if (digit == num % 10)
			return true;

		num /= 10;
	}

	return false;
}

bool isValidGuess(int guess)
{
	if (guess < 0) return false;

	bool recordedDigits[10] = { 0 };
	recordedDigits[0] = true; // We don't have zeroes in secret number

	for (int i = 0; i < NUMBER_LENGTH; i++)
	{
		if (guess == 0 || recordedDigits[guess % 10])
			return false;
		
		recordedDigits[guess % 10] = true;
		guess /= 10;
	}

	return guess == 0; // False if wider than NUMBER_LENGTH digits
}

void countBullsAndCows(int secretNum, int guess, int *bulls, int *cows)
{
	*bulls = *cows = 0;
	
	 // If our secret num can contain zeroes, this (and the corresponding checks) should be changed to some other digit
	int secretCows = 0, guessCows = 0; 

	for (int i = 0; i < NUMBER_LENGTH; i++)
	{
		if (guess % 10 == secretNum % 10)
			*bulls += 1;
		else
		{
			secretCows = secretCows * 10 + secretNum % 10;
			// If the guess (and secret) can have duplicate digits, this should be done only with the unique ones
			guessCows = guessCows * 10 + guess % 10;
		}

		secretNum /= 10;
		guess /= 10;
	}

	while (secretCows != 0)
	{
		if (digitInsideNum(secretCows % 10, guessCows))
			*cows += 1;

		secretCows /= 10;
	}
}

void playBullsAndCows()
{
	int secNum = genSecretNum(), guess = 0, bulls = 0, cows = 0;

	for (int i = 0; i < N; i++)
	{
		cin >> guess;

		if (!isValidGuess(guess))
		{
			cout << "Your guess is invalid!" << endl;
		}
		else if (guess == secNum)
		{
			cout << "You win!" << endl;
			return;
		}
		else
		{
			countBullsAndCows(secNum, guess, &bulls, &cows);
			cout << bulls << " bulls and " << cows << " cows" << endl;
		}
	}

	cout << "You lose! The number was " << secNum << " and you couldn't guess it in " << N << " guesses!" << endl;
}

void ex4()
{
	playBullsAndCows();
}

int main()
{
	ex4();
}