From 849ec965b365a26a343a905ab47f13ee7612a414 Mon Sep 17 00:00:00 2001
From: rzuckerm <ron.zuckerman@adtran.com>
Date: Sat, 31 May 2025 13:36:06 -0500
Subject: [PATCH 1/3] Fix bug in example and tests for Baffling Birthdays

---
 .../baffling-birthdays/.meta/BafflingBirthdays.example.ps1    | 4 ++--
 .../practice/baffling-birthdays/BafflingBirthdays.tests.ps1   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1 b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
index 648bdba..bb74598 100644
--- a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
+++ b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
@@ -16,13 +16,13 @@ Function Invoke-BafflingBirthdays {
     Param(
         [int]$People
     )
-    $runs = 1000
+    $runs = 5000
     $count = 0
     for ($i = 0; $i -lt $runs; $i++) {
         $birthdays = Get-RandomBirthdates -People $People
         $count += Test-SharedBirthday -Birthdates $birthdays
     }
-    $count /  100.00
+    $count * 100.00 / $runs
 }
 
 Function Get-RandomBirthdate([int]$Year) {
diff --git a/exercises/practice/baffling-birthdays/BafflingBirthdays.tests.ps1 b/exercises/practice/baffling-birthdays/BafflingBirthdays.tests.ps1
index 676578b..626aa28 100644
--- a/exercises/practice/baffling-birthdays/BafflingBirthdays.tests.ps1
+++ b/exercises/practice/baffling-birthdays/BafflingBirthdays.tests.ps1
@@ -139,9 +139,9 @@ Describe "BafflingBirthdays test cases" {
 
     Context "estimated probability" {
         BeforeAll {
-            $tolerance = 1
+            $tolerance = 2
             function Test-Probability($Probability, $Expected, $Tolerance) {
-                ($Probability -ge $Expected - $Tolerance) -or ($Probability -le $Expected + $Tolerance)
+                ($Probability -ge $Expected - $Tolerance) -and ($Probability -le $Expected + $Tolerance)
             }
         }
 

From 4fd7ccc8a880a5d8841c63eb109b7eeebd8762e6 Mon Sep 17 00:00:00 2001
From: rzuckerm <ron.zuckerman@adtran.com>
Date: Sat, 31 May 2025 14:35:58 -0500
Subject: [PATCH 2/3] Speed up example by generating random number from 0 to
 365 and adding it to Jan 1 of the year

---
 .../.meta/BafflingBirthdays.example.ps1          | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1 b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
index bb74598..ca236d1 100644
--- a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
+++ b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
@@ -19,18 +19,11 @@ Function Invoke-BafflingBirthdays {
     $runs = 5000
     $count = 0
     for ($i = 0; $i -lt $runs; $i++) {
-        $birthdays = Get-RandomBirthdates -People $People
-        $count += Test-SharedBirthday -Birthdates $birthdays
+        $count += Test-SharedBirthday -Birthdates (Get-RandomBirthdates -People $People)
     }
     $count * 100.00 / $runs
 }
 
-Function Get-RandomBirthdate([int]$Year) {
-    $month = Get-Random -Minimum 1 -Maximum (12 + 1)
-    $day   = Get-Random -Minimum 1 -Maximum (([DateTime]::DaysInMonth($Year, $month)) + 1)
-    [datetime]::New($Year, $month, $day)
-}
-
 Function Get-RandomBirthdates {
     <#
     .SYNOPSIS
@@ -47,9 +40,8 @@ Function Get-RandomBirthdates {
         $year = Get-Random -Minimum 1900 -Maximum ((Get-Date).Year + 1)
     } until (-not [DateTime]::IsLeapYear($year))
 
-    for ($i = 0; $i -lt $People; $i++) {
-        Get-RandomBirthdate $year
-    }
+    Get-Random -Minimum 0 -Maximum 365 -Count $People |
+        ForEach-Object { [DateTime]::new($year, 1, 1).AddDays($_) }
 }
 
 Function Test-SharedBirthday {
@@ -64,7 +56,7 @@ Function Test-SharedBirthday {
     Param(
         [DateTime[]]$Birthdates
     )
-    for ($i = 0; $i -lt $Birthdates.Count; $i++) {
+    for ($i = 0; $i -lt $Birthdates.Count - 1; $i++) {
         for ($j = $i+1; $j -lt $Birthdates.Count; $j++) {
             if ($Birthdates[$i].DayOfYear -eq $Birthdates[$j].DayOfYear) {
                 return $true

From d314af0526fa48685940bad791be7df46546cbf8 Mon Sep 17 00:00:00 2001
From: glaxxie <86179463+glaxxie@users.noreply.github.com>
Date: Sat, 31 May 2025 14:58:54 -0500
Subject: [PATCH 3/3] Update docstring

---
 .../baffling-birthdays/.meta/BafflingBirthdays.example.ps1     | 3 +++
 exercises/practice/baffling-birthdays/BafflingBirthdays.ps1    | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1 b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
index ca236d1..3a9baa4 100644
--- a/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
+++ b/exercises/practice/baffling-birthdays/.meta/BafflingBirthdays.example.ps1
@@ -11,6 +11,9 @@ Function Invoke-BafflingBirthdays {
 
     .PARAMETER People
     Number of people in the group.
+
+    .NOTES
+    Consider doing 5000 runs of the test for optimal result for 2% tolerance.
     #>
     [CmdletBinding()]
     Param(
diff --git a/exercises/practice/baffling-birthdays/BafflingBirthdays.ps1 b/exercises/practice/baffling-birthdays/BafflingBirthdays.ps1
index ae69293..cb69aca 100644
--- a/exercises/practice/baffling-birthdays/BafflingBirthdays.ps1
+++ b/exercises/practice/baffling-birthdays/BafflingBirthdays.ps1
@@ -11,6 +11,9 @@ Function Invoke-BafflingBirthdays {
 
     .PARAMETER People
     Number of people in the group.
+
+    .NOTES
+    Consider doing 5000 runs of the test for optimal result for 2% tolerance.
     #>
     [CmdletBinding()]
     Param(