From b91feb76ff86703dee16ff7d2c72d75ecbafed10 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Wed, 1 Jul 2026 14:42:06 +0200
Subject: [PATCH 1/7] Add `square-root` exercice

---
 config.json                                   |  8 +++
 .../square-root/.docs/instructions.md         | 18 +++++
 .../square-root/.docs/introduction.md         | 10 +++
 .../practice/square-root/.meta/config.json    | 19 ++++++
 .../practice/square-root/.meta/example.php    | 14 ++++
 .../practice/square-root/.meta/tests.toml     | 28 ++++++++
 exercises/practice/square-root/SquareRoot.php | 30 ++++++++
 .../practice/square-root/SquareRootTest.php   | 68 +++++++++++++++++++
 8 files changed, 195 insertions(+)
 create mode 100644 exercises/practice/square-root/.docs/instructions.md
 create mode 100644 exercises/practice/square-root/.docs/introduction.md
 create mode 100644 exercises/practice/square-root/.meta/config.json
 create mode 100644 exercises/practice/square-root/.meta/example.php
 create mode 100644 exercises/practice/square-root/.meta/tests.toml
 create mode 100644 exercises/practice/square-root/SquareRoot.php
 create mode 100644 exercises/practice/square-root/SquareRootTest.php

diff --git a/config.json b/config.json
index 56444532..478afd6c 100644
--- a/config.json
+++ b/config.json
@@ -489,6 +489,14 @@
           "floating_point_numbers"
         ]
       },
+      {
+        "slug": "square-root",
+        "name": "Square Root",
+        "uuid": "d75c009b-ad65-455f-a824-ed61c8797cc4",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "transpose",
         "name": "Transpose",
diff --git a/exercises/practice/square-root/.docs/instructions.md b/exercises/practice/square-root/.docs/instructions.md
new file mode 100644
index 00000000..d258b868
--- /dev/null
+++ b/exercises/practice/square-root/.docs/instructions.md
@@ -0,0 +1,18 @@
+# Instructions
+
+Your task is to calculate the square root of a given number.
+
+- Try to avoid using the pre-existing math libraries of your language.
+- As input you'll be given a positive whole number, i.e. 1, 2, 3, 4…
+- You are only required to handle cases where the result is a positive whole number.
+
+Some potential approaches:
+
+- Linear or binary search for a number that gives the input number when squared.
+- Successive approximation using Newton's or Heron's method.
+- Calculating one digit at a time or one bit at a time.
+
+You can check out the Wikipedia pages on [integer square root][integer-square-root] and [methods of computing square roots][computing-square-roots] to help with choosing a method of calculation.
+
+[integer-square-root]: https://en.wikipedia.org/wiki/Integer_square_root
+[computing-square-roots]: https://en.wikipedia.org/wiki/Methods_of_computing_square_roots
diff --git a/exercises/practice/square-root/.docs/introduction.md b/exercises/practice/square-root/.docs/introduction.md
new file mode 100644
index 00000000..1d692934
--- /dev/null
+++ b/exercises/practice/square-root/.docs/introduction.md
@@ -0,0 +1,10 @@
+# Introduction
+
+We are launching a deep space exploration rocket and we need a way to make sure the navigation system stays on target.
+
+As the first step in our calculation, we take a target number and find its square root (that is, the number that when multiplied by itself equals the target number).
+
+The journey will be very long.
+To make the batteries last as long as possible, we had to make our rocket's onboard computer very power efficient.
+Unfortunately that means that we can't rely on fancy math libraries and functions, as they use more power.
+Instead we want to implement our own square root calculation.
diff --git a/exercises/practice/square-root/.meta/config.json b/exercises/practice/square-root/.meta/config.json
new file mode 100644
index 00000000..05869605
--- /dev/null
+++ b/exercises/practice/square-root/.meta/config.json
@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "resu-xuniL"
+  ],
+  "files": {
+    "solution": [
+      "SquareRoot.php"
+    ],
+    "test": [
+      "SquareRootTest.php"
+    ],
+    "example": [
+      ".meta/example.php"
+    ]
+  },
+  "blurb": "Given a natural radicand, return its square root.",
+  "source": "wolf99",
+  "source_url": "https://github.com/exercism/problem-specifications/pull/1582"
+}
diff --git a/exercises/practice/square-root/.meta/example.php b/exercises/practice/square-root/.meta/example.php
new file mode 100644
index 00000000..76f17305
--- /dev/null
+++ b/exercises/practice/square-root/.meta/example.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+function squareRoot(int $number): int
+{
+    $sqrt = $number;
+
+    while (pow($sqrt, 2) > $number) {
+        $sqrt--;
+    }
+
+    return $sqrt;
+}
diff --git a/exercises/practice/square-root/.meta/tests.toml b/exercises/practice/square-root/.meta/tests.toml
new file mode 100644
index 00000000..ead7882f
--- /dev/null
+++ b/exercises/practice/square-root/.meta/tests.toml
@@ -0,0 +1,28 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[9b748478-7b0a-490c-b87a-609dacf631fd]
+description = "root of 1"
+
+[7d3aa9ba-9ac6-4e93-a18b-2e8b477139bb]
+description = "root of 4"
+
+[6624aabf-3659-4ae0-a1c8-25ae7f33c6ef]
+description = "root of 25"
+
+[93beac69-265e-4429-abb1-94506b431f81]
+description = "root of 81"
+
+[fbddfeda-8c4f-4bc4-87ca-6991af35360e]
+description = "root of 196"
+
+[c03d0532-8368-4734-a8e0-f96a9eb7fc1d]
+description = "root of 65025"
diff --git a/exercises/practice/square-root/SquareRoot.php b/exercises/practice/square-root/SquareRoot.php
new file mode 100644
index 00000000..a12efa02
--- /dev/null
+++ b/exercises/practice/square-root/SquareRoot.php
@@ -0,0 +1,30 @@
+<?php
+
+/*
+ * By adding type hints and enabling strict type checking, code can become
+ * easier to read, self-documenting and reduce the number of potential bugs.
+ * By default, type declarations are non-strict, which means they will attempt
+ * to change the original type to match the type specified by the
+ * type-declaration.
+ *
+ * In other words, if you pass a string to a function requiring a float,
+ * it will attempt to convert the string value to a float.
+ *
+ * To enable strict mode, a single declare directive must be placed at the top
+ * of the file.
+ * This means that the strictness of typing is configured on a per-file basis.
+ * This directive not only affects the type declarations of parameters, but also
+ * a function's return type.
+ *
+ * For more info review the Concept on strict type checking in the PHP track
+ * <link>.
+ *
+ * To disable strict typing, comment out the directive below.
+ */
+
+declare(strict_types=1);
+
+function squareRoot(int $number): int
+{
+    throw new \BadMethodCallException(sprintf('Implement the %s function', __FUNCTION__));
+}
diff --git a/exercises/practice/square-root/SquareRootTest.php b/exercises/practice/square-root/SquareRootTest.php
new file mode 100644
index 00000000..3644d98e
--- /dev/null
+++ b/exercises/practice/square-root/SquareRootTest.php
@@ -0,0 +1,68 @@
+<?php
+
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+use PHPUnit\Framework\Attributes\TestDox;
+
+class SquareRootTest extends TestCase
+{
+    public static function setUpBeforeClass(): void
+    {
+        require_once 'SquareRoot.php';
+    }
+
+    /**
+     * uuid: 9b748478-7b0a-490c-b87a-609dacf631fd
+     */
+    #[TestDox('root of 1')]
+    public function testRootOfOne(): void
+    {
+        $this->assertEquals(1, squareRoot(1));
+    }
+
+    /**
+     * uuid: 7d3aa9ba-9ac6-4e93-a18b-2e8b477139bb
+     */
+    #[TestDox('root of 4')]
+    public function testRootOfFour(): void
+    {
+        $this->assertEquals(2, squareRoot(4));
+    }
+
+    /**
+     * uuid: 6624aabf-3659-4ae0-a1c8-25ae7f33c6ef
+     */
+    #[TestDox('root of 25')]
+    public function testRootOfTwentyFive(): void
+    {
+        $this->assertEquals(5, squareRoot(25));
+    }
+
+    /**
+     * uuid: 93beac69-265e-4429-abb1-94506b431f81
+     */
+    #[TestDox('root of 81')]
+    public function testRootOfEightyOne(): void
+    {
+        $this->assertEquals(9, squareRoot(81));
+    }
+
+    /**
+     * uuid: fbddfeda-8c4f-4bc4-87ca-6991af35360e
+     */
+    #[TestDox('root of 196')]
+    public function testRootOfOneHundredNinetySix(): void
+    {
+        $this->assertEquals(14, squareRoot(196));
+    }
+
+    /**
+     * uuid: c03d0532-8368-4734-a8e0-f96a9eb7fc1d
+     */
+    #[TestDox('root of 65025')]
+    public function testRootOfSixtyFiveThousandTwentyFive(): void
+    {
+        $this->assertEquals(255, squareRoot(65025));
+    }
+}

From b9741ff22a32609e3372e80b546c1bb5a139bc13 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Thu, 2 Jul 2026 08:29:08 +0200
Subject: [PATCH 2/7] Update `auto-sync.txt` and add exercice

---
 bin/auto-sync.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/bin/auto-sync.txt b/bin/auto-sync.txt
index 3d2c7dfb..6143429b 100644
--- a/bin/auto-sync.txt
+++ b/bin/auto-sync.txt
@@ -29,6 +29,7 @@ etl
 flatten-array
 flower-field
 food-chain
+game-of-life
 gigasecond
 grade-school
 grains
@@ -68,6 +69,7 @@ rail-fence-cipher
 raindrops
 resistor-color
 resistor-color-duo
+resistor-color-trio
 reverse-string
 rna-transcription
 robot-name
@@ -83,6 +85,7 @@ series
 sieve
 space-age
 spiral-matrix
+square-root
 state-of-tic-tac-toe
 strain
 sublist

From 01a06e99e96d2573a3a1868d296a8c2b4bde5ecc Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Thu, 2 Jul 2026 20:57:07 +0200
Subject: [PATCH 3/7] Change difficulty rating

---
 config.json | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/config.json b/config.json
index 478afd6c..f9d90050 100644
--- a/config.json
+++ b/config.json
@@ -296,14 +296,6 @@
         "prerequisites": [],
         "difficulty": 1
       },
-      {
-        "slug": "crypto-square",
-        "name": "Crypto Square",
-        "uuid": "14aa815d-8073-4a71-841e-9bfdba4b0b1a",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 1
-      },
       {
         "slug": "diamond",
         "name": "Diamond",
@@ -585,6 +577,14 @@
           "math"
         ]
       },
+      {
+        "slug": "crypto-square",
+        "name": "Crypto Square",
+        "uuid": "14aa815d-8073-4a71-841e-9bfdba4b0b1a",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "darts",
         "name": "Darts",

From a9074c13907d117a4ae46d398905d2fc1f50a495 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Thu, 2 Jul 2026 20:58:06 +0200
Subject: [PATCH 4/7] Add test "not use or mention PHP square root functions"

---
 exercises/practice/square-root/SquareRootTest.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/exercises/practice/square-root/SquareRootTest.php b/exercises/practice/square-root/SquareRootTest.php
index 3644d98e..8d741692 100644
--- a/exercises/practice/square-root/SquareRootTest.php
+++ b/exercises/practice/square-root/SquareRootTest.php
@@ -12,6 +12,14 @@ public static function setUpBeforeClass(): void
         require_once 'SquareRoot.php';
     }
 
+    #[TestDox('does not use or mention PHP square root functions')]
+    public function testDoesNotUseOrMentionPhpSquareRootFunctions(): void
+    {
+        $code = file_get_contents('SquareRoot.php');
+
+        $this->assertStringNotContainsString('sqrt(', $code);
+    }
+
     /**
      * uuid: 9b748478-7b0a-490c-b87a-609dacf631fd
      */

From 9418979bc431f2d27b789d0143b59b6dd7cc33b9 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Thu, 2 Jul 2026 21:06:30 +0200
Subject: [PATCH 5/7] Fix path

---
 exercises/practice/square-root/SquareRootTest.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/exercises/practice/square-root/SquareRootTest.php b/exercises/practice/square-root/SquareRootTest.php
index 8d741692..486402ff 100644
--- a/exercises/practice/square-root/SquareRootTest.php
+++ b/exercises/practice/square-root/SquareRootTest.php
@@ -15,7 +15,7 @@ public static function setUpBeforeClass(): void
     #[TestDox('does not use or mention PHP square root functions')]
     public function testDoesNotUseOrMentionPhpSquareRootFunctions(): void
     {
-        $code = file_get_contents('SquareRoot.php');
+        $code = file_get_contents(__DIR__ . '/SquareRoot.php');
 
         $this->assertStringNotContainsString('sqrt(', $code);
     }

From 9ffb85435b7053845426e006c13be8b82bea11e1 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Fri, 3 Jul 2026 19:10:30 +0200
Subject: [PATCH 6/7] Add message for assertion validation

---
 exercises/practice/square-root/.meta/example.php  | 8 ++++----
 exercises/practice/square-root/SquareRootTest.php | 2 +-
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/exercises/practice/square-root/.meta/example.php b/exercises/practice/square-root/.meta/example.php
index 76f17305..46e79fcd 100644
--- a/exercises/practice/square-root/.meta/example.php
+++ b/exercises/practice/square-root/.meta/example.php
@@ -4,11 +4,11 @@
 
 function squareRoot(int $number): int
 {
-    $sqrt = $number;
+    $squareRoot = $number;
 
-    while (pow($sqrt, 2) > $number) {
-        $sqrt--;
+    while (pow($squareRoot, 2) > $number) {
+        $squareRoot--;
     }
 
-    return $sqrt;
+    return $squareRoot;
 }
diff --git a/exercises/practice/square-root/SquareRootTest.php b/exercises/practice/square-root/SquareRootTest.php
index 486402ff..ef66b769 100644
--- a/exercises/practice/square-root/SquareRootTest.php
+++ b/exercises/practice/square-root/SquareRootTest.php
@@ -17,7 +17,7 @@ public function testDoesNotUseOrMentionPhpSquareRootFunctions(): void
     {
         $code = file_get_contents(__DIR__ . '/SquareRoot.php');
 
-        $this->assertStringNotContainsString('sqrt(', $code);
+        $this->assertStringNotContainsString('sqrt', $code, 'Please do not use the word "sqrt" anywhere in your code!');
     }
 
     /**

From 3a6caae76ef0881f8231b544cc45c0151ff0dac2 Mon Sep 17 00:00:00 2001
From: resu-xuniL <linux@lavache.com>
Date: Fri, 3 Jul 2026 19:35:05 +0200
Subject: [PATCH 7/7] Fix `config.json`

---
 config.json | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

diff --git a/config.json b/config.json
index f9d90050..13f89f4a 100644
--- a/config.json
+++ b/config.json
@@ -296,6 +296,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "crypto-square",
+        "name": "Crypto Square",
+        "uuid": "14aa815d-8073-4a71-841e-9bfdba4b0b1a",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "diamond",
         "name": "Diamond",
@@ -481,14 +489,6 @@
           "floating_point_numbers"
         ]
       },
-      {
-        "slug": "square-root",
-        "name": "Square Root",
-        "uuid": "d75c009b-ad65-455f-a824-ed61c8797cc4",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 1
-      },
       {
         "slug": "transpose",
         "name": "Transpose",
@@ -577,14 +577,6 @@
           "math"
         ]
       },
-      {
-        "slug": "crypto-square",
-        "name": "Crypto Square",
-        "uuid": "14aa815d-8073-4a71-841e-9bfdba4b0b1a",
-        "practices": [],
-        "prerequisites": [],
-        "difficulty": 2
-      },
       {
         "slug": "darts",
         "name": "Darts",
@@ -736,6 +728,14 @@
           "strings"
         ]
       },
+      {
+        "slug": "square-root",
+        "name": "Square Root",
+        "uuid": "d75c009b-ad65-455f-a824-ed61c8797cc4",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "strain",
         "name": "Strain",