https://www.codewars.com/kata/dont-give-me-five/train/php

dont-give-me-five.php

<?php
function dont_give_me_five(int $start, int $end): int
{
    $start_multiple = $start < 0 ? -1 : 1;
    $end_multiple = $end < 0 ? -1 : 1;

    $zero_value = (int)(
        $start_multiple !== $end_multiple
        || false === strpos((string)min(abs($start), abs($end)), '5')
    );

    if ($start == $end) {
        return $zero_value;
    }

    return (
        abs(
            five_0_to_num(abs($start)) * $start_multiple
            - five_0_to_num(abs($end)) * $end_multiple
        )
        + $zero_value
    );
}

function five_0_to_num(int $value): int
{
    assert($value >= 0, 'Optimization: abs first');
    if (!$value) {
        return 0;
    }

    $string = (string)$value;
    if ($string[0] == 5) {
        $string = '4' . str_repeat('9', strlen($string) - 1);
        $value = (int)$string;
    }

    $last = ($string[0] - ($string[0] > 4 ? 1 : 0)) * pow(9, strlen($string) - 1);

    return $last + five_0_to_num((int)mb_substr($value, 1));
}


/**
 * class DontGiveMeFiveTest extends TestCase {
 * public function testSimple()
 * {
 * $this->assertEquals(8, dont_give_me_five(1, 9));
 * $this->assertEquals(12, dont_give_me_five(4, 17));
 * }
 *
 * public function testWithEthalon()
 * {
 * $test_array = [0, 1, 5, 105, 150, 500, 555, 444, 446, 600, 99999];
 * foreach ($test_array as $xx) {
 * foreach ([-1, 1] as $xm) {
 * $x = $xx * $xm;
 * foreach ($test_array as $yy) {
 * foreach ([-1, 1] as $ym) {
 * $y = $yy * $ym;
 *
 * $this->assertEquals(
 * $this->ethalon($x, $y),
 * dont_give_me_five($x, $y),
 * "$x => $y with: " . $this->ethalon($x, $y) . '!='. dont_give_me_five($x, $y)
 * );
 * }
 * }
 * }
 * }
 *
 * $this->assertEquals(
 * 2477039237406838187,
 * dont_give_me_five(PHP_INT_MIN + 1, PHP_INT_MAX - 1),
 * 'PHP_INT_MIN => PHP_INT_MAX'
 * );
 * }
 *
 * public function testTime()
 * {
 *
 * $microtime1 = microtime(true);
 * $my_result = dont_give_me_five(PHP_INT_MIN + 1, PHP_INT_MAX - 1);
 * $microtime2 = microtime(true);
 * var_dump([
 * "my" => [
 * 'value' => $my_result,
 * 'time' => ceil(($microtime2 - $microtime1)*10000)/10000,
 * ]
 * ]);
 *
 * $microtime3 = microtime(true);
 * $ethalon_result = $this->ethalon(PHP_INT_MIN + 1, PHP_INT_MAX - 1);
 * $microtime4 = microtime(true);
 *
 * var_dump([
 * "ethalon" => [
 * 'value' => $my_result === $ethalon_result,
 * 'diff' => ceil(($microtime4-$microtime3) - ($microtime2-$microtime1))/1000 .'s',
 * ],
 * ]);
 * }
 *
 *
 * public function ethalon(int $start, int $end):int
 * {
 * if ($start > $end) {
 * list($start, $end) = [$end, $start];
 * }
 * $count = 0;
 * for ($x = $start; $x <= $end; ++$x) {
 * if (strpos($x, '5') === false) {
 * $count++;
 * }
 * }
 *
 * return $count;
 * }
 * }
 */

$test_array = [0, 1, 5, 105, 150, 500, 555, 444, 446, 600, 99999];

foreach ($test_array as $xx) {
    foreach ([-1, 1] as $xm) {
        $x = $xx * $xm;
        foreach ($test_array as $yy) {
            foreach ([-1, 1] as $ym) {
                $y = $yy * $ym;
                $r = [
                    ethalon($x, $y),
                    dont_give_me_five($x, $y)
                ];
                if ($r[0] != $r[1]) {
                    var_dump(["$x => $y" => $r]);
                } else {
                    echo '.';
                }
            }
        }
    }
}

$microtime1 = microtime(true);
$my_result = dont_give_me_five(PHP_INT_MIN + 1, PHP_INT_MAX - 1);
$microtime2 = microtime(true);
var_dump([
    "my" => [
        'value' => $my_result,
        'time' => ceil(($microtime2 - $microtime1) * 10000) / 10000,
    ]
]);

$microtime3 = microtime(true);
$ethalon_result = ethalon(PHP_INT_MIN + 1, PHP_INT_MAX - 1);
$microtime4 = microtime(true);

var_dump([
    "ethalon" => [
        'value' => $my_result === $ethalon_result,
        'diff' => ceil(($microtime4 - $microtime3) - ($microtime2 - $microtime1)) / 1000 . 's',
    ],
]);

$microtime5 = microtime(true);
$ethalon2_result = ethalon2(PHP_INT_MIN + 1, PHP_INT_MAX - 1);
$microtime6 = microtime(true);

var_dump([
    "ethalon" => [
        'value' => $my_result === $ethalon2_result,
        'diff' => ceil(($microtime6 - $microtime5) - ($microtime2 - $microtime1)) / 1000 . 's',
    ],
]);

function ethalon(int $start, int $end): int
{
    if ($start > $end) {
        list($start, $end) = [$end, $start];
    }
    $count = 0;
    for ($x = $start; $x <= $end; ++$x) {
        if (strpos($x, '5') === false) {
            $count++;
        }
    }

    return $count;
}

function ethalon2(int $start, int $end): int
{
    return count(array_filter(range($start, $end), function ($iNumber) {
        return strpos((string)$iNumber, '5') === false;
    }));
}