Fixes

- added simple main
- fixed private constructors
- added docs

src/main/java/net/berack/upo/ai/Main.java

@@ -1,8 +1,38 @@
 package net.berack.upo.ai;
 
+import java.util.Scanner;
+import java.util.function.Function;
+
+import net.berack.upo.ai.problem1.Puzzle8GUI;
+import net.berack.upo.ai.problem2.TrisGUI;
+
 public class Main {
 
     public static void main(String[] args) {
+        var value = read("What do you want to play?\n1. Puzzle8\n2. Tris\n", new Scanner(System.in), num -> num > 0 && num < 2);
+        var window = switch (value) {
+            case 1 -> new Puzzle8GUI();
+            case 2 -> new TrisGUI();
+            default -> null;
+        };
 
+        if(window != null) {
+            window.toFront();
+            window.requestFocus();
+        }
+    }
+
+    private static int read(String out, Scanner in, Function<Integer, Boolean> control) {
+        var ret = 0;
+
+        do {
+            try {
+                System.out.print(out);
+                var str = in.nextLine();
+                ret = Integer.parseInt(str);
+            } catch (NumberFormatException ignore) {}
+        } while(!control.apply(ret));
+
+        return ret;
     }
 }