add brain-prime

Makefile

@@ -16,6 +16,9 @@ brain-gcd:
 brain-progression:
 	./bin/brain-progression
 
+brain-prime:
+	./bin/brain-prime
+
 validate:
 	composer validate
 

bin/brain-prime

@@ -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\Prime\play();

composer.json

@@ -5,7 +5,8 @@
         "bin/brain-even",
         "bin/brain-calc",
         "bin/brain-gcd",
-        "bin/brain-progression"
+        "bin/brain-progression",
+        "bin/brain-prime"
     ],
     "description": "Brain game",
     "type": "project",
@@ -23,7 +24,8 @@
             "src/Games/Even.php",
             "src/Games/Calc.php",
             "src/Games/Gcd.php",
-            "src/Games/Progression.php"
+            "src/Games/Progression.php",
+            "src/Games/Prime.php"
         ]
     },
     "scripts": {

src/Games/Prime.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Brain\Games\Prime;
+
+use function Brain\Engine\gameLogic;
+use function cli\line;
+use function cli\prompt;
+
+const DESCRIPTION = 'Answer "yes" if given number is prime. Otherwise answer "no".';
+const RANDOM_MIN = 2;
+const RANDOM_MAX = 20;
+
+function isPrime($number)
+{
+    if ($number < 2) {
+        return false;
+    }
+    for ($i = 2; $i <= $number / 2; $i += 1) {
+        if ($number % $i == 0) {
+            return false;
+        }
+    }
+    return true;
+}
+
+function getAnswer($question)
+{
+    $answer = isPrime($question) ? 'yes' : 'no';
+    return $answer;
+}
+
+function getRandomNumber()
+{
+    return rand(RANDOM_MIN, RANDOM_MAX);
+}
+
+function play()
+{
+    $generateGameData = function () {
+        $question = getRandomNumber();
+        $answer = getAnswer($question);
+
+        return [$question, $answer];
+    };
+
+    gameLogic(DESCRIPTION, $generateGameData);
+    return;
+}