PHP - Patterns within Arrays

I am trying to create a function which maps a recurring pattern of integers using an array.

As an example if I have a starting array of (0,1,3) and I know that I want to stop the pattern when I hit 15.

The pattern gets incremented by a fixed integer each time (lets say 4) so my f开发者_高级运维inal pattern should be..

0
1
3
4 (0 + 4)
5 (1 + 4)
7 (2 + 4)
8 (4 + 4)
9 (5 + 4)
11(7 + 4)
12(8 + 4)
13(9 + 4)
15(11+ 4)

Does anyone have any pointers on how this can be achieved?

My current implementation works but is stupidly inefficient which something like this...

$array = array(0,1,3);
$inc = 4;
$end = end($array);
$final = 15;

while($end < $final)
{
$tmp = array();
foreach($array AS $row)
{
$tmp = $row + $inc;
}
$array = merge($tmp, $array);
$end = end($array);
}

$array = array(0,1,3);
$inc = 4;
$final = 15;
$end = end($array);

while($end < $final)
{
  $end += $inc;
  $array[] = $end;
}

Or with a for loop:

$array = array(0,1,3);
$inc = 4;
$final = 15;

for($i = end($array) + $inc; $i <= $final; $i += $inc)
{
  $array[] = $i;
}

Y'all are missing the fact that 4 is being added to the value in the array 2 keys back, not the last value.

This is the code you need (tested, and working)

$array = array(0,1,3);
$inc = 4;
$end = end($array);
$key = key($array);
$final = 15;

while ($end < $final) {
    if ($array[$key-2] >= 0) {
        $end = $array[$key-2] + $inc;
        $array[] = $end;
        $key++;
    }
}

I also included in there a check to make sure the key being added to actually exists, though that may not be needed.

I assume that you want to have all the new values in the same array. So:

//original array
$values =  array(0, 1, 3);

//incremental value
$inc = 4;
//stop value
$stop = 15;

//set the index counter to the origin
$curr_index = 0;

//while the last value of the array is lower than the stop value
while($values[end($values)] < $stop)
{
    //calculate the new value
    $new_value = $values[$curr_index] + $inc;
    //add the new value to the array
    array_push($values, $new_value);
    //update the index counter
    $curr_index ++;
}

this code should work for any initial value in the array, any incremental value and any stop value.

<?php

function myArrayFunction(array $array, $inc = 4, $final = 15, $end = null)
{
    if(!$end)
    {
        $end = end($array);
    }

    while($end < $final)
    {
        $end += $inc;
        $array[] = $end;
    }

    return $array; //assume you're wanting $array back
}

This is minus any sort of testing or checking of injected values but you get the idea.

It would be better to know what you are trying to achieve here as the whole thing looks horribly overcomplicated, but...

$array = array(0,1,3);
$pattern = array();
$inc = 4;
$final = 15;

for ($base = 0; ; $base += $inc) {
  foreach($array as $rem) {
    if ($base + $rem > $final) break 2;
    $pattern []= $base + $rem;
  }
}

Alternatively,

$i = $v = 0;
while ($v < $final) {
  $v = $pattern []= $pattern[$i++] + $inc;
}

(This assumes $final will be part of the pattern.)

If you can figure out how to calculate the number of elements will be in the array beforehand and assign that to $tum this should work.

<?php

$arr = array(0, 1, 3);
$inc = 4; // 6
$fin = 15; // 55
$num = count($arr);
$lum = 0;
$tum = 12; // 29

do
{
    for($i = $lum; $i < $num; $i++)
    {
        $tar        = $arr[$i] + $inc;
        $arr[$tar]  = $tar;
    }
    $lum = $num;
    $num *= 2;
} while(end($arr) < $fin);

$arr = array_slice($arr, 0, $tum);

print_r($arr);
echo "\n";

?>