40 lines
999 B
PHP
40 lines
999 B
PHP
<?php
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$starting_numbers = explode(',', file_get_contents('input.txt'));
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$tmp_numbers = array_map('intval', $starting_numbers);
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$count_numbers = [];
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foreach ($tmp_numbers as $i => $tmp_number) {
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if (array_key_exists($tmp_number, $count_numbers)) {
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$count_numbers[$tmp_number][] = $i;
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} else {
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$count_numbers[$tmp_number] = [$i];
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}
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}
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$number = end($tmp_numbers);
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unset($tmp_numbers, $tmp_number);
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for ($i = count($starting_numbers); $i <= 29999999; $i++) {
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$number = newNumber($i, $number);
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}
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echo $number;
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function newNumber(int $i, int $number = 0)
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{
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global $count_numbers;
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if (!array_key_exists($number, $count_numbers)) {
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$count_numbers[$number] = [$i];
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return $number;
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}
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$count_indexes = count($count_numbers[$number]);
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$new_number = $count_indexes === 1 ? 0 : $count_numbers[$number][$count_indexes - 1] - $count_numbers[$number][$count_indexes - 2];
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$count_numbers[$new_number][] = $i;
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return $new_number;
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}
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