checkstyle fixes

Author: walpurr

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

@@ -1,8 +1,11 @@
 package hexlet.code;
 
 import java.util.Scanner;
-
-import hexlet.code.games.*;
+import hexlet.code.games.Even;
+import hexlet.code.games.Calc;
+import hexlet.code.games.GCD;
+import hexlet.code.games.Progression;
+import hexlet.code.games.Prime;
 
 public class App {
     public static void main(String[] args) {

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

@@ -24,11 +24,11 @@ public static void start() {
             var number2 = Engine.getRandomNumber(RANDOM_NUMBER_BOUND);
             char operator;
 
-            switch (Engine.getRandomNumber(RANDOM_OPERATOR_BOUND)) {
-                case 0 -> operator = '+';
-                case 1 -> operator = '-';
-                default -> operator = '*';
-            }
+            operator = switch (Engine.getRandomNumber(RANDOM_OPERATOR_BOUND)) {
+                case 0 -> '+';
+                case 1 -> '-';
+                default -> '*';
+            };
 
             var correctAnswer = calculate(number1, number2, operator);
             questions[i] = number1 + " " + operator + " " + number2;

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

@@ -1,7 +1,5 @@
 package hexlet.code.games;
 
-import java.util.Scanner;
-
 public class GCD {
     private static final int RANDOM_NUMBER_BOUND = 100;
 

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

@@ -1,6 +1,5 @@
 package hexlet.code.games;
 
-import java.util.Scanner;
 import java.util.StringJoiner;
 
 public class Progression {