Just PHP FUN 002.

divistors.php

<?php
# https://www.codewars.com/kata/544aed4c4a30184e960010f4 Find the divisors!.
function divisors($integer) {
  $answer = [];
  for($i = 2; $i < $integer; $i++)
    if(0 == $integer%$i) array_push($answer,$i);
  if(empty($answer)) return "$integer is prime";
  return $answer;
}

generate_integers.php

<?php
# https://www.codewars.com/kata/5841f680c5c9b092950001ae Series of integers from m to n.
function generate_integers(int $m, int $n): array {
  return range($m,$n);
}

just_php_fun_002.md

Just PHP FUN 002.

• https://www.codewars.com/kata/559e3224324a2b6e66000046 Functions of Integers on Cartesian Plane.
• https://www.codewars.com/kata/51675d17e0c1bed195000001 Largest 5 digit number in a series.
• https://www.codewars.com/kata/5841f680c5c9b092950001ae Series of integers from m to n.
• https://www.codewars.com/kata/544aed4c4a30184e960010f4 Find the divisors!.
• https://www.codewars.com/kata/582c297e56373f0426000098 Convert a linked list to a string.

Started at 20:48 20.05.2020 Wednesday May.
Finised at 22:11 20.05.2020 Wednesday May. (1hr 37minutes).

largest_5.php

<?php
# https://www.codewars.com/kata/51675d17e0c1bed195000001 Largest 5 digit number in a series.
function solution(string $s): int {
  $array = str_split($s);
  $max = intval(join('',array_slice($array,0,5)));
  $cur = $max;
  for($i=5; $i < count($array); $i++){
    $cur = ($cur*10)%(10**5) + (int)$array[$i];
    if($max < $cur) $max = $cur;
  }
  return $max;
}

lst_to_str.php

<?php
# https://www.codewars.com/kata/582c297e56373f0426000098 Convert a linked list to a string.
function stringify($list): string {
  $ans = "";
  while($list){
    $tmp = $list->data;
    $ans .= "$tmp -> ";
    $list = $list->next;
  }
  $ans .= "NULL";
  return $ans;
}

sum_Cartesian_plane.php

<?php
# https://www.codewars.com/kata/559e3224324a2b6e66000046 Functions of Integers on Cartesian Plane.
function suma($n){
  return (($n+1)*$n)/2;
}
function sumin($n) {
    $z = suma($n) * $n;
    $tmp = 0;
    for($i=1; $i < $n; $i++){
      $tmp += $i;
      $z -= $tmp;
    }
    return $z;
}
function sumax($n) {
    $z = suma($n) * $n;
    $tmp = 0;
    for($i=1; $i < $n; $i++){
      $tmp += $i;
      $z += $tmp;
    }
    return $z;
}
function sumsum($n) {
    return sumin($n)+sumax($n);
}