add brain-gcd

Makefile

@@ -10,6 +10,9 @@ brain-even:
 brain-calc:
 	./bin/brain-calc
 
+brain-gcd:
+	./bin/brain-gcd
+
 validate:
 	composer validate
 

bin/brain-gcd

@@ -0,0 +1,14 @@
+#!/usr/bin/env php
+
+<?php
+
+$autoloadPath1 = __DIR__ . '/../../../autoload.php';
+$autoloadPath2 = __DIR__ . '/../vendor/autoload.php';
+
+if (file_exists($autoloadPath1)) {
+    require_once $autoloadPath1;
+} else {
+    require_once $autoloadPath2;
+}
+
+Brain\Games\Gcd\play();

composer.json

@@ -3,7 +3,8 @@
     "bin": [
         "bin/brain-games",
         "bin/brain-even",
-        "bin/brain-calc"
+        "bin/brain-calc",
+        "bin/brain-gcd"
     ],
     "description": "Brain game",
     "type": "project",
@@ -19,7 +20,8 @@
             "src/Cli.php",
             "src/Engine.php",
             "src/Games/Even.php",
-            "src/Games/Calc.php"
+            "src/Games/Calc.php",
+            "src/Games/Gcd.php"
         ]
     },
     "scripts": {

src/Engine.php

@@ -9,10 +9,10 @@
 
 function gameLogic($gameConditionsEven, $generateGameData)
 {
-    line("Welcome to the Brain Games! \n");
-    line($gameConditionsEven);
+    line("Welcome to the Brain Games!");
     $name = prompt("May I have your name?");
     line("Hello, {$name}!");
+    line($gameConditionsEven);
 
     for ($i = 1; $i <= CORRECT_ANSWER; $i += 1) {
         [$question, $answer] = $generateGameData();

src/Games/Gcd.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Brain\Games\Gcd;
+
+use function Brain\Engine\gameLogic;
+use function cli\line;
+use function cli\prompt;
+
+const DESCRIPTION = 'Find the greatest common divisor of given numbers.';
+const RANDOM_MIN = 1;
+const RANDOM_MAX = 20;
+
+function gcd($a, $b)
+{
+    if ($b === 0) {
+        return abs($a);
+    }
+    return gcd($b, $a % $b);
+}
+
+function getRandomNumber()
+{
+    return rand(RANDOM_MIN, RANDOM_MAX);
+}
+
+function play()
+{
+    $generateGameData = function () {
+        $firstNumber = getRandomNumber();
+        $secondNumber = getRandomNumber();
+        $question = "{$firstNumber} {$secondNumber}";
+        $answer = (string)(gcd($firstNumber, $secondNumber));
+
+        return [$question, $answer];
+    };
+
+    gameLogic(DESCRIPTION, $generateGameData);
+    return;
+}