sort 2d array based on another array - php

Question

i have a 1D arrayA and a 2D arrayB.
arrayA[0] = 'D'
arrayA[1] = 'U'
arrayA[3] = 'R'
arrayA[4] = 'B'
arrayA[5] = 'S'
arrayA[6] = 'H'
arrayB[0][0] = 'D' arrayB[0][1] = 2
arrayB[1][0] = 'B' arrayB[1][1] = 1
arrayB[2][0] = 'R' arrayB[2][1] = 1
arrayB[3][0] = 'U' arrayB[3][1] = 1
arrayB[4][0] = 'H' arrayB[4][1] = 0
arrayB[5][0] = 'S' arrayB[5][1] = 0
arrayB[x][y] is sorted - based on y.
I have to create a new array using the letters, first giving priority on y from arrayB[x][y].
But there are some same values in y like, 1 three times and 0 two times.
In this situation similar values will be sorted according to arrayA.
and the new array will sort like :
D, U, R, B, S, H
How can i do it efficiently ?
thanks in advance

Answer 1

In the code below, $string corresponds to arrayB[x][0], $weight corresponds to arrayB[x][1] and $order corresponds to arrayA:
<?php
$string = str_split('DBRUHS');
$weight = str_split('211100');
$result = '';
function my_sort($a, $b)
{
$order = str_split('DURBSH');
$a = array_search($a, $order);
$b = array_search($b, $order);
if ($a === $b) return 0;
if ($a === FALSE) return -1;
if ($b === FALSE) return 1;
if ($a == $b) return 0;
return ($a < $b) ? -1 : 1;
}
arsort($weight);
$current_priority = -1;
$substring = array();
$max = count($weight);
$count = 1;
foreach ($weight as $position => $priority)
{
if ($count++ == $max)
{
$substring[] .= $string[$position];
$priority = $current_priority + 1;
}
if ($current_priority != $priority)
{
if (!empty($substring))
{
usort($substring, 'my_sort');
$result .= implode('', $substring);
}
$current_priority = $priority;
$substring = array($string[$position]);
}
else
{
$substring[] = $string[$position];
}
}
print_r(str_split($result));
?>

Answer 2

I tried this and it worked fine. a1 is the 1d array, a2 is the 2d.
EDIT: This works now.
function sortArr($a1, $a2) {
$t1 = array();
foreach ($a1 as $v) {
$t2 = array();
foreach ($a2 as $i=>$k) {
if ($k[0] == $v) {
$t2[0] = $k[0];
$t2[1] = $k[1];
$t1[$i] = $t2;
break;
}
}
}
return $t1;
}