add game GCD

Author: Prototype206

README.md

@@ -16,5 +16,9 @@
 ![Calc win](screenshots/CalcGame-win.png)
 ### Defeat in the app Calc 
 ![Calc lose](screenshots/CalcGame-lose.png)
+### Victory in the app GCD 
+![GCD win](screenshots/GCDGame-win.png)
+### Defeat in the app GCD 
+![GCD lose](screenshots/GCDGame-lose.png)
 ### Exiting the app   
 ![Exit](screenshots/Exiting-app.png)

app/src/main/java/hexlet/code/App.java

@@ -3,13 +3,14 @@
 
 import hexlet.code.games.Calc;
 import hexlet.code.games.Even;
+import hexlet.code.games.GCD;
 
 public class App {
 	public static void main(String[] args) {
 		Scanner scanner = new Scanner(System.in);
 		try {
 		System.out.println("Please enter the game number and press Enter.");
-		System.out.print("1 - Greet\n2 - Even\n3 - Cacl\n0 - Exit\nYour choice: ");
+		System.out.print("1 - Greet\n2 - Even\n3 - Cacl\n4 - GCD\n0 - Exit\nYour choice: ");
 		int usersChoise = 0;
 
 		try {
@@ -33,6 +34,11 @@ public static void main(String[] args) {
 			Calc.startGameCalc();
 			Engine.runGame(Engine.CALC_GAME_NUMBER, scanner);
 			break;
+		case 4:
+			Cli.greetings(scanner);
+			GCD.startGameGCD();
+			Engine.runGame(Engine.GCD_GAME_NUMBER, scanner);
+			break;
 		case 0:
 			break;
 		}

app/src/main/java/hexlet/code/Engine.java

@@ -4,6 +4,7 @@
 
 import hexlet.code.games.Calc;
 import hexlet.code.games.Even;
+import hexlet.code.games.GCD;
 
 public class Engine {
 	private static int scoreCounter = 0;
@@ -12,19 +13,24 @@ public class Engine {
 	private static StringBuilder usersAnswer = new StringBuilder();
 	static final int EVEN_GAME_NUMBER = 2;
 	static final int CALC_GAME_NUMBER = 3;
+	static final int GCD_GAME_NUMBER = 4;
 
 	public static void runGame(int gameNumber, Scanner scanner) {
 		for(int i = 0; i<scoreToWin; i++) {
 			correctAnswer.setLength(0);
 			usersAnswer.setLength(0);
+			
 			switch(gameNumber) {
 			case EVEN_GAME_NUMBER:
 				correctAnswer.append(Even.generateCorrectAnswer());
 				break;
 			case CALC_GAME_NUMBER:
 				correctAnswer.append(Calc.generateCorrectAnswer());
 				break;
+			case GCD_GAME_NUMBER:
+				correctAnswer.append(GCD.generateCorrectAnswer());
 			}
+			
 			System.out.print("Your answer: ");
 			usersAnswer.append(scanner.nextLine());
 			if(usersAnswer.toString().equals(correctAnswer.toString())) {

app/src/main/java/hexlet/code/games/GCD.java

@@ -0,0 +1,28 @@
+package hexlet.code.games;
+
+public class GCD {
+	private static int numberA;
+	private static int numberB;
+	private static int numberC;
+	
+	public static void startGameGCD() {
+		System.out.println("Find the greatest common divisor of given numbers.");
+	}
+	
+	public static String generateCorrectAnswer() {
+		numberA = (int) (Math.random()*100);
+		numberB = (int) (Math.random()*100);
+		System.out.println("Question: " + numberA + " " + numberB);
+		while(true) {
+			if(numberB > 0) {
+				numberC = numberA;
+				numberA = numberB;
+				numberB = numberC % numberB;
+			}
+			else {
+				break;
+			}
+		}
+		return String.valueOf(numberA);
+	}
+}