<?php
 
$total = numberOfReplacements('Привeт', 'Привет', 'Cyrillic');
echo "Замена киррилицы латиницей: $total симв.\n";
 
$total = numberOfReplacements('hаbr', 'habr', 'Latin');
echo "Замена латиницы киррилицей: $total симв.";
 
 
function numberOfReplacements(string $input, string $original, string $pattern): int
{
    $pattern = preg_quote($pattern, '~');
    $match = preg_match_all("~\p{{$pattern}}~u", $input);
    $total = mb_strlen($original);
 
    return $total - $match;
}

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