fix linter issues

Author: Aleksandr Pronichev

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

@@ -19,29 +19,29 @@ public static void main(String[] args) {
                 0 - Exit""");
 
         System.out.print("Your choice: ");
-        int choice = scanner.nextInt();
+        String choice = scanner.nextLine();
         System.out.println();
 
         switch (choice) {
-            case 1:
+            case "1":
                 Cli.greeting();
                 break;
-            case 2:
+            case "2":
                 Even.gameEven();
                 break;
-            case 3:
+            case "3":
                 Calc.gameCalc();
                 break;
-            case 4:
+            case "4":
                 GCD.gameGCD();
                 break;
-            case 5:
+            case "5":
                 Progression.gameProgression();
                 break;
-            case 6:
+            case "6":
                 Prime.gamePrime();
                 break;
-            case 0:
+            case "0":
                 break;
             default:
                 System.out.println("Please select 1, 2, 3, 4, 5, 6 or 0.");

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

@@ -5,15 +5,16 @@
 public class Calc {
 
     private static final String RULES = "What is the result of the expression?";
+    private static final int MAX_NUMBER = 100;
 
     public static void gameCalc() {
         String[] questions = new String[Engine.ROUNDS];
         String[] correctAnswers = new String[Engine.ROUNDS];
         String[] operators = {"+", "-", "*"};
 
         for (int i = 0; i < Engine.ROUNDS; i++) {
-            int firstNumber = (int) (Math.random() * 100);
-            int secondNumber = (int) (Math.random() * 100);
+            int firstNumber = (int) (Math.random() * MAX_NUMBER);
+            int secondNumber = (int) (Math.random() * MAX_NUMBER);
             String operator = operators[(int) (Math.random() * operators.length)];
             questions[i] = firstNumber + " " + operator + " " + secondNumber;
 

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

@@ -5,13 +5,14 @@
 public class Even {
 
     private static final String RULES = "Answer 'yes' if the number is even, otherwise answer 'no'.";
+    private static final int MAX_NUMBER = 100;
 
     public static void gameEven() {
         String[] questions = new String[Engine.ROUNDS];
         String[] correctAnswers = new String[Engine.ROUNDS];
 
         for (int i = 0; i < Engine.ROUNDS; i++) {
-            int number = (int) (Math.random() * 100);
+            int number = (int) (Math.random() * MAX_NUMBER);
             questions[i] = Integer.toString(number);
             if (number % 2 == 0) {
                 correctAnswers[i] = "yes";

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

@@ -5,14 +5,15 @@
 public class GCD {
 
     private static final String RULES = "Find the greatest common divisor of given numbers.";
+    private static final int MAX_NUMBER = 100;
 
     public static void gameGCD() {
         String[] questions = new String[Engine.ROUNDS];
         String[] correctAnswers = new String[Engine.ROUNDS];
 
         for (int i = 0; i < Engine.ROUNDS; i++) {
-            int firstNumber = (int) (Math.random() * 100);
-            int secondNumber = (int) (Math.random() * 100);
+            int firstNumber = (int) (Math.random() * MAX_NUMBER);
+            int secondNumber = (int) (Math.random() * MAX_NUMBER);
             questions[i] = firstNumber + " " + secondNumber;
             int gcd = calculateGCD(firstNumber, secondNumber);
             correctAnswers[i] = Integer.toString(gcd);

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

@@ -5,13 +5,14 @@
 public class Prime {
 
     private static final String RULES = "Answer 'yes' if given number is prime. Otherwise answer 'no'.";
+    private static final int MAX_NUMBER = 100;
 
     public static void gamePrime() {
         String[] questions = new String[Engine.ROUNDS];
         String[] correctAnswers = new String[Engine.ROUNDS];
 
         for (int i = 0; i < Engine.ROUNDS; i++) {
-            int number = (int) (Math.random() * 100);
+            int number = (int) (Math.random() * MAX_NUMBER);
             questions[i] = Integer.toString(number);
             if (isPrime(number)) {
                 correctAnswers[i] = "yes";

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

@@ -5,15 +5,19 @@
 public class Progression {
 
     private static final String RULES = "What number is missing in the progression?";
+    private static final int MIN_LENGTH = 5;
+    private static final int MAX_LENGTH = 10;
+    private static final int MAX_START = 10;
+    private static final int MAX_STEP = 10;
 
     public static void gameProgression() {
         String[] questions = new String[Engine.ROUNDS];
         String[] correctAnswers = new String[Engine.ROUNDS];
 
         for (int i = 0; i < Engine.ROUNDS; i++) {
-            int progressionLength = (int) (Math.random() * 6) + 5;
-            int start = (int) (Math.random() * 10);
-            int step = (int) (Math.random() * 10) + 1;
+            int progressionLength = (int) (Math.random() * (MAX_LENGTH - MIN_LENGTH + 1)) + MIN_LENGTH;
+            int start = (int) (Math.random() * MAX_START);
+            int step = (int) (Math.random() * MAX_STEP) + 1;
 
             int[] progression = new int[progressionLength];