<?php
const min = 1;	 # начало
	  $N  = 1000;   # всего
	  
	  $DP = 1;	 # ~ процент повторов
	  $DC = 0;	 # количество повторов (при генерации)

$BS = rand(min, ($N + 1));

$numbers = range(min, ($N + 1));

shuffle($numbers);

foreach ($numbers as $i => $number) {
	if (
		rand(0, 99) < $DP &&
		$BS !== $number
	) {
		$numbers[$i] = $BS;
		$DC++;
	}
}

shuffle($numbers);

// алгоритм

$BadSeed;

//

print "bad seed: $BS \n";
print "повторов: $DC \n";
print "нашел bad seed: $BadSeed \n";