Add Gcd game

Author: prusov-code

Makefile

@@ -10,3 +10,5 @@ brain-even:
 	./bin/brain-even
 brain-calc:
 	./bin/brain-calc
+brain-gcd:
+	./bin/brain-gcd

bin/brain-gcd

@@ -0,0 +1,7 @@
+#!/usr/bin/env php
+
+<?php
+
+require __DIR__."/../vendor/autoload.php";
+
+\BrainGames\GcdGame\startGcdGame();

composer.json

@@ -7,13 +7,15 @@
         "files": [
             "src/Cli.php",
             "src/EvenGame.php",
-            "src/CalcGame.php"
+            "src/CalcGame.php",
+            "src/GcdGame.php"
         ]
     },
     "bin": [
         "bin/brain-games",
         "bin/brain-even",
-        "bin/brain-calc"
+        "bin/brain-calc",
+        "bin/brain-gcd"
     ],
     "authors": [
         {

src/GcdGame.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace BrainGames\GcdGame;
+
+use function BrainGames\Cli\playGame;
+
+function startGcdGame(): void
+{
+    $questions = [];
+    $answers = [];
+    for ($i = 0; $i < 3; $i++) {
+        $number1 = rand(1, 100);
+        $number2 = rand(1, 100);
+
+        $questions[$i] = "{$number1} {$number2}";
+        $answers[$i] = findGcd($number1, $number2);
+    }
+    playGame($questions, $answers, 'Find the greatest common divisor of given numbers.');
+}
+
+function findGcd(int $number1, int $number2): int
+{
+    while ($number2 !== 0) {
+        $tempNumber2 = $number2;
+        $number2 = $number1 % $number2;
+        $number1 = $tempNumber2;
+    }
+    return $number1;
+}