Group the same array element in PHP - php

Question

I have this function to check for word sequences:
function sequence($arr_scheme = [], $arr_input = [])
{
$sequence_need = array_values(array_intersect($arr_scheme, $arr_input));
if(!empty($arr_input) && ($sequence_need == $arr_input)):
return true;
else:
return false;
endif;
}
There were my sample and scheme variables:
$sample = "branch of science";
$scheme = "The branch of science concerned of nature and property of matter and energy";
I have converted to array:
$arr_sample = explode(" ",trim(rtrim(rtrim($sample,".")," ")));
echo 'Sample:';
var_dump($arr_sample);
$arr_scheme = explode(" ",trim(rtrim(rtrim($scheme,".")," ")));
echo '<br/>Scheme:';
var_dump($arr_scheme);
Now, I check the sequences:
$result = sequence($arr_scheme, $arr_sample);
The result:
echo '<br/>Result:';
var_dump($result);
When I set the variable $sample to
"branch science" the result will return true. This was fine.
However when I set the variable sample to
"branch of science" the result will return false .
Reason - the word of was more than 1, how I can solve this problem?

Answer 1

Find first input word in the scheme (can be multiple).
Then run recursive for rests of arrays.
function sequence($arr_scheme = [], $arr_input = [])
{
if (!$arr_input) return true;
$first = array_shift($arr_input);
$occurences = array_keys($arr_scheme, $first);
if (!$occurences) return false;
foreach ($occurences as $o) { // loop first word occurences
$found = sequence(array_slice($arr_scheme, $o), $arr_input);
if ($found) return true;
}
return false;
}
First word later occurences should not matter anything for match.
So, this tail-recursion function will work even better:
function sequence($arr_scheme = [], $arr_input = [])
{
if (!$arr_input) return true;
$first = array_shift($arr_input);
$index = array_search($arr_scheme, $first);
if ($index === false) return false; // not found
return sequence(array_slice($arr_scheme, $index), $arr_input);
}

Answer 2

You can research more at here. Note: "Returns an array containing all of the values in array1 whose values exist in all of the parameters.". Then, look at in your result, when you call var_dump($arr_scheme);, you see "of" appears 3 times. and size of array result after compare is 5. however, size of array $sample is 3. So, you can understand why it returns false.
Solution for this case. why dont you try to use regular expression? or strpos function?

Answer 3

$sequence_need = array_unique($sequence_need);
array_unique removes any duplicate values in your array.. the duplicate 'of' will be removes.. Hope it helps..

Answer 4

I think you should go with array_diff(). It computes the difference of arrays and returns the values in $arr_sample that are not present in $arr_scheme.
So,
array_diff($arr_sample, $arr_scheme)
will return an empty array if all the values in $arr_sample are present in $arr_scheme
The next step would be to count the length of the array returned by array_diff(). If it equals 0, then we should return true
return count(array_diff($arr_sample, $arr_scheme)) === 0;
The above return statement could be presented as:
$diff = array_diff($arr_sample, $arr_scheme);
if (count($diff) === 0) {
return true;
} else {
return false;
}
From your comments it became clear that your function should return true
if all the elements of $arr_input are present in $arr_scheme in the same order
that they appear in $arr_scheme. Othewise it should return false
So,
sequence(['branch', 'of', 'science', 'and', 'energy'], ['branch', 'of', 'energy'])
should return true
and
sequence(['branch', 'of', 'science', 'and', 'energy'], ['science', 'of', 'branch'])
should return false
In this case the function sequence() could be defined as follows:
function sequence($arr_scheme = [], $arr_input = [])
{
//test if all elements of $arr_input are present in $arr_scheme
$diff = array_diff($arr_input, $arr_scheme);
if ($diff) {
return false;
}
foreach ($arr_input as $value) {
$pos = array_search($value, $arr_scheme);
if (false !== $pos ) {
$arr_scheme = array_slice($arr_scheme, $pos + 1);
continue;
}
return false;
}
return true;
}