php numbers script array loop - php

Question

I try to write a script and a problem. Can you let me know if you know how i can do this or ask someone if they know how can this be possibe.
Max numbers which can be selected 1 to 20 numbers. it can loop and select any number between 1-20
ignore these numbers e.g. 1,2,4,6,9,12 this will be array which can change.
each array line can have upto 4 numbers
Each array line needs to be unique
5.I need to have around 10 arrays unique
Max 2 numbers can match previous numbers see below.
How can i go about doing this. Any help would be great.
e.g.
Array(
[0] => Array
(
[0] => 3
[1] => 16
[2] => 22
[3] => 24
)
[1] => Array
(
[0] => 3
[1] => 16
[2] => 7
[3] => 13
)
[2] => Array
(
[0] => 20
[1] => 17
[2] => 10
[3] => 18
)
)
This not allow as some array match each other
Array(
[0] => Array
(
[0] => 3
[1] => 16
[2] => 22
[3] => 24
)
[1] => Array - cant have this as 3 of the numbers matchs the previous array.only two numbers can match.
(
[0] => 3
[1] => 16
[2] => 22
[3] => 13
)
[2] => Array
(
[0] => 20
[1] => 17
[2] => 10
[3] => 18
)
)
Thank you.

Answer 1

This seems to satisfy your conditions: http://codepad.viper-7.com/WHkQeD
<?php
$num_arrays = 10; $num_elements = 4;
$min = 1; $max = 20;
$exclude_numbers = array( 1, 4, 6); // Add numbers here to exclude
$answer = array();
for( $i = 0; $i < $num_arrays; $i++)
{
$answer[$i] = array();
for( $j = 0; $j < $num_elements; $j++)
{
do
{
$current = rand( $min, $max);
// If the previous array exists and there are more than two common elements when we add the $current element, continue
if( isset( $answer[$i-1]) && count( array_intersect( $answer[$i-1], array_merge( $answer[$i], array( $current))) > 2)
{
continue;
}
} while( in_array( $current, $exclude_numbers) || in_array( $current, $answer[$i]));
$answer[$i][$j] = $current;
}
}
var_dump( $answer);
Edit: Here is a complete solution that satisfies all of your criteria.
Demo
<?php
$num_arrays = 10; $num_elements = 4;
$min = 1; $max = 20;
$exclude_numbers = array( 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13);
$answer = array();
for( $i = 0; $i < $num_arrays; $i++)
{
$answer[$i] = array();
for( $j = 0; $j < $num_elements; $j++)
{
do
{
// Get a random element
$current = rand( $min, $max);
$new_array = array_merge( $answer[$i], array( $current));
// If the previous array has more than two common elements (because of the added $current), get a new $current
if( isset( $answer[$i-1]) && count( array_intersect( $answer[$i-1], $new_array)) > 2)
{
$answer[$i] = array_diff( $new_array, $answer[$i-1]);
$j = count( $answer[$i]) - 1;
continue;
}
} while( in_array( $current, $exclude_numbers) || in_array( $current, $answer[$i]));
$answer[$i][$j] = $current;
// If the array is complete, we need to check for unique arrays
if( count( $answer[$i]) == $num_elements)
{
$k = $i - 1;
while( $k >= 0)
{
if( count( array_diff( $answer[$k], $answer[$i])) == 0)
{
// This array is the same as a previous one, start over
$answer[$i] = array();
$j = -1;
break;
}
$k--;
}
// Optionally sort each array
sort( $answer[$i]);
}
}
}
var_dump( $answer);

Answer 2

somthing like:
function generate_list($max, $forbidden)
{
$list = array();
while(count($list) < 4)
{
$new = rand(1, $max);
if(in_array($new, $forbidden))
{
continue;
}
$list[] = $new;
$forbidden[] = $new;
}
return $list;
}
function count_max_same($new_list, $old_lists)
{
$max_same = 0;
foreach($old_lists as $current_list)
{
$max_same = max($max_same, count(array_intersect($new_list, $old_lists)));
}
return $max_same;
}
function generate_unique_lists($count_of_lists, $max, $forbidden, $max_same = 2, $max_tries = 1000)
{
$lists = array();
while($max_tries-- AND count($lists) < $count_of_lists)
{
$new_list = generate_list($max, $forbidden);
if(count_max_same($new_list, $lists) <= $max_same)
{
$lists[] = $new_list;
}
}
return $lists;
}