Just PHP FUN 123.

just_php_fun_123.md

Just PHP FUN 123.

• https://www.codewars.com/kata/5324945e2ece5e1f32000370 Sum Strings as Numbers.

Started at 22:36 at 08.10.2020 at Thursday Oct.
Finished at 23:04 at 08.10.2020 at Thursday Oct. (0hrs 28minutes)

sum_strings.php

<?php
# https://www.codewars.com/kata/5324945e2ece5e1f32000370 Sum Strings as Numbers.
function sum_strings($a, $b) {
  return $a + $b;
}
# -----------------------------------------------------------------------------
function sum_strings($a, $b) {
  $max = max(strlen($a),strlen($b));
  /*echo "Start. $max; \n";
  echo "$a \n";
  echo "$b \n";*/
  
  $a = to_a($a,$max);
  $b = to_a($b,$max);
  $ans = "";
  $nxt = 0;  
  for($i = 0; $i < $max; $i += 1){
     $tmp = intval($a[$i]) + intval($b[$i]) + $nxt;
     $nxt = $tmp >= 10 ? 1 : 0;
     $ans = strval($tmp%10).$ans;
  }
  if(1 == $nxt) $ans = "1".$ans;
  if(1 < strlen($ans)) $ans = preg_replace('/^0+/',"",$ans);
  //echo "$ans \n";
  return $ans;

}
function to_a($str,$max){
  $padd = str_pad($str,$max,"0",STR_PAD_LEFT);
  return array_reverse(str_split($padd));
}