N random numbers that can duplicate after 2 elements - php

Question

I want to generate 10 numbers with each ranging from (1 to 5) but can only duplicate after 2 elements
for example 5 3 1 4 2 5(can be duplicated here) 2 (cannot be duplicate here since it occur before 1 element) ...etc.
I have this code in php working but its performance is awful since it sometimes exceeds the maximum 30 seconds execution time.
<?php
function contain($prevItems, $number) {
if (count($prevItems) == 3)
{
array_shift($prevItems);
}
for ($k=0; $k<count($prevItems); $k++) {
if ($prevItems[$k] == $number)
return true;
}
return false;
}
$num[0] = rand(1,5);
$prevItems[0] = $num[0];
for ($i=1; $i<=10; $i++) {
$num[$i] = rand(1,5);
while (contain($prevItems, $num[$i])) {
$num[$i] = rand (1,5);
}
$prevItems[$i] = $num[$i]; //append into the array
}
print_r($num);
?>
Edit:
I have also tried this method, its performance is good but it duplicates elements
<?php
$evalAccurance = array();
$count = 0;
while ( $count < 11)
{
$random = rand(1, 5);
if (in_array($random, $evalAccurance))
{
$p = $random;
for ($k = $p ; $k <5; $k++)
{
$random = $random++;
if (in_array($random, $evalAccurance))
continue 1;
else break 1;
}
if (in_array($random, $evalAccurance))
{
for ($k = $p ; $k >0; $k--)
{
$random = $random--;
if (in_array($random, $evalAccurance))
continue 1;
else break 1;
}
}
}
$evalAccurance[] = $random;
if (count ($evalAccurance) == 4)
array_shift($evalAccurance);
print_r ($evalAccurance);
$count++;
}
?>

Answer 1

One way you could do this:
// pass to function current array of numbers
function randomNumber($ar){
// create a random number from 1 to 5
$num = rand(1,5);
// check backwards 3 elements for same number, if none found return it
if(!in_array($num, array_slice($ar, -3, 3, true))){
return $num;
} else {
// else recall function with same array of numbers
return randomNumber($ar);
}
}
$array = array();
// loop 10 numbers and call randomNumber with current set of results.
for($i=1; $i<=10; $i++){
$array[] = randomNumber($array);
}
print_r($array);

Answer 2

Using PHP SPLQueue:
$queue = new SplQueue();
$values = array(1, 2, 3, 4, 5);
$container = array();
for ($i = 0; $i < 10; $i++) {
$value = give_random($values, $queue);
$container[] = $value;
if ($queue->offsetExists(1) AND $queue->offsetExists(0)) {
$queue->dequeue();
}
$queue->enqueue($value);
}
function give_random(&$values, &$queue) {
$picked_value = $values[array_rand($values)];
if ($queue->offsetExists(1)) {
if ($picked_value == $queue->offsetGet(1)) {
$picked_value = give_random($values, $queue);
}
}
if ($queue->offsetExists(0)) {
if ($picked_value == $queue->offsetGet(0)) {
$picked_value = give_random($values, $queue);
}
}
return $picked_value;
}
print_r($container);
It could be neater, but you can figure what's going on.
Cheers.