game_1.ino

// BUTTON PINS
const int buttonPin_1 = 2;
const int buttonPin_2 = 3;
const int buttonPin_3 = 4;
const int buttonPin_4 = 5;
const int buttonPin_reset = 5;

// GAME OPTIONS
const int defaultValue = 16;
const int minValue = 5;
const int maxValue = 60;
const int winValue = 49;

// GAME STATES
const int gameState_new = 2;
const int gameState_playing = 3;
const int gameState_win = 4;

// CURRENT GAME STATE
int gameState = gameState_new;

// BUTTON PINS LIST
int buttonPins[] = {
	buttonPin_1,
	buttonPin_2,
	buttonPin_3,
	buttonPin_4,
	buttonPin_reset
};

// BUTTON STATES LIST
int buttonStates[] = {
	LOW,
	LOW,
	LOW,
	LOW,
	LOW
};

// BUTTON FLAGS LIST (`HIGH` IF WAS PRESSED)
int buttonValues[] = {
	LOW,
	LOW,
	LOW,
	LOW,
	LOW
};

// BUTTON MODIFIERS LIST (HOW BUTTON MODIFIES CURRENT GAME VALUE)
int buttonModifier[] = {
  +9,
  -9,
	+6,
	-6,
	0 // because reset button
}

// CURRENT GAME VALUE
int currentValue = 16;

// ARDUINO SYSTEM METHOD TO INITIALIZE PINS
void setup() {
  // BUTTON PINS INITIALIZE
  for(int i = 0; i < sizeof(buttonPins); i++) {
		pinMode(buttonPins[i], INPUT);
  }
}

// Read buttons state by pins, calculate that button was pressed
void updateStates() {
	int currentState;
  for(int i = 0; i < sizeof(buttonPins); i++) {
		currentState = digitalRead(buttonPins[i]);
		if(buttonStates[i] != HIGH) {
			buttonStates[i] = currentState;
		} else if(currentState == LOW) {
			buttonStates[i] = LOW;
			buttonValues[i] = HIGH;
		}
  }
}

// Checking number by game rules
void checkNumber() {
	if(currentValue < minValue || currentValue > maxValue) {
		currentValue = defaultValue;
	} else if(currentValue = winValue) {
		gameState = gameState_win;
	}
}

// Get button state, if was pressed it's returns HIGH and reseting state
int getButtonState(i) {
	int result = buttonValues[i];
  if(result == HIGH) {
		buttonValues[i] = LOW;
	}

	return result;
}

// Update states of all entities
void process() {
	// update buttons state
	updateStates();
	// checking buttons values: value is HIGH if button was pressed
  for(int i = 0; i < sizeof(buttonPins); i++) {
		if(getButtonState(i) == HIGH) {
			// means that button was pressed

			if(buttonPins[i] == buttonPin_reset) {
				// if reset button was pressed, resetting game value & set game state to `new`
				currentValue = defaultValue;
				gameState = gameState_new;
			} else {
				// if one of 4 game buttons pressed updating game value and setting gameState to `playing`
				currentValue += buttonModifier[i];
				gameState = gameState_playing;
			}
		}
	}
}

// Main loop
void loop() {
	// Updating buttons and game states
  process();

	// Checking game state
	if(gameState == gameState__playing) {
		// Game value was updated, need to check it
		checkNumber();
	}

	// checking game state after number check
	if(gameState == gameState_win) {
		//@todo exit, player win
	}
}