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Sum of first N prime numbers
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| 3 | |
| 4 | |
| 100 | |
| 100 | |
| 1000 |
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| <?php | |
| function get_next_prime_number($number) { | |
| while (true) { | |
| $number++; | |
| $divider = floor($number / 2); | |
| $is_prime = true; | |
| while ($divider > 1) { | |
| if ($number % $divider == 0) { | |
| $is_prime = false; | |
| break; | |
| } | |
| $divider--; | |
| } | |
| if ($is_prime) { | |
| return $number; | |
| } | |
| } | |
| } | |
| function get_prime_numbers($count = 2) { | |
| static $numbers = [2, 3]; | |
| for ($i = count($numbers); $i < $count; $i++) { | |
| $last_number = end($numbers); | |
| $numbers[] = get_next_prime_number($last_number); | |
| } | |
| return array_slice($numbers, 0, $count); | |
| } | |
| $data = fopen('data.txt', 'r'); | |
| while($line = fgets($data)) { | |
| echo array_sum(get_prime_numbers($line)) . "\n"; | |
| } |
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