Just PHP FUN 018.

distinctDigitYear.php

<?php
# https://www.codewars.com/kata/58aa68605aab54a26c0001a6 Simple Fun #144: Distinct Digit Year.
function distinctDigitYear($year) {
  $year += 1;
  $distincts = function($x){
    $array = str_split($x);
    $uniq = array_unique($array);
    return count($array) == count($uniq);
  };
  while(!$distincts($year)) $year += 1;
  return $year;
}

invite_more_women.php

<?php
# https://www.codewars.com/kata/58acfe4ae0201e1708000075 Simple Fun #152: Invite More Women?
function invite_more_women(array $a): bool {
  return array_sum($a) > 0;
}

just_php_fun_018.md

Just PHP FUN 018.

• https://www.codewars.com/kata/58acfe4ae0201e1708000075 Simple Fun #152: Invite More Women?
• https://www.codewars.com/kata/58845748bd5733f1b300001f Simple Fun #10: Range Bit Counting.
• https://www.codewars.com/kata/58aa68605aab54a26c0001a6 Simple Fun #144: Distinct Digit Year.
• https://www.codewars.com/kata/581e476d5f59408553000a4b Fun with lists: length.
• https://www.codewars.com/kata/5bb804397274c772b40000ca Stacked Balls - 2D.

Started at 21:40 08.06.2020 Monday June.
Finished at 23:24 08.02.2020 Monday June. (1hr 44minutes)

length.php

<?php
# https://www.codewars.com/kata/581e476d5f59408553000a4b Fun with lists: length.
function length($head) {
  $length = 0;
  while($head){
    $head = $head->next;
    $length += 1;
  }
  return $length;
}

range_bit_count.php

<?php
# https://www.codewars.com/kata/58845748bd5733f1b300001f Simple Fun #10: Range Bit Counting.
function range_bit_count(int $a, int $b): int {
  $x = range($a,$b);
  return array_reduce($x,function($a, $x){
  echo "$a and $x =>".decbin($x)." \n";
  return $a + substr_count(decbin($x),1);},0);
}

stackHeight2d.php

<?php
# https://www.codewars.com/kata/5bb804397274c772b40000ca Stacked Balls - 2D.
function ($n) {
  if( 0 == $n) return 0;
  if( 1 == $n) return 1;
  return round(sqrt((3/4)*($n-1)*($n-1))+1,3);
}

https://youtu.be/LWXFmcionxI