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I have an array of 20 different numbers which contains ranking of students.
I want to split this array into two sub arrays of equal length i.e 10
I also want the sum of all numbers within each array to be close.
For example, in sub-array A there could be a total sum of 56 and in sub-array B there could be a total sum of 57.
I am using PHP.
I sort the main array here and would like to assign index[0] to sub-array A and index[1] to sub-array B, and keep repeating this until both arrays are filled.
My approach works but i think its not great and not dynamic.
I interate through the main original array for [i] and then add that to the first sub-array, then I set i = i+2 so that I get every second value and store them in the first array.
I then remove the value at index[i] from the main array.
What is left over is now sub-array B.
$kids = array (8,5,6,9,3,8,2,4,6,10,8,5,6,1,7,10,5,3,7,6);
sort($kids);
$arrlength = count($kids);
for($x = 0; $x < $arrlength; $x++) {
echo $kids[$x];
echo "<br>";
}
$teamA = array();
$teamB = array();
$i = 0;
while ($i < $arrlength)
{
#echo $kids[$i] ."<br />";
array_push($teamA, $kids[$i]);
unset($kids[$i]);
$i += 2;
}
$teamB = $kids;
print_r($teamA);
print_r($teamB);
My Output is :
Array ( [0] => 1 [1] => 3 [2] => 4 [3] => 5 [4] => 6 [5] => 6 [6] => 7 [7] =>
8 [8] => 8 [9] => 10 )
The sum here of all values is = 58
Array ( [1] => 2 [3] => 3 [5] => 5 [7] => 5 [9] => 6
[11] => 6 [13] => 7 [15] => 8 [17] => 9 [19] => 10 )
The sum here of all values is = 61
Any help is greatly appreciated. I have no real experience with PHP or its built in functions so sorry if this is a basic question. Thanks!
There is a built-in helper function of php, array_slice. You can read about it in the link I provided.
Here's how you can use in to achieve what you want:
$kids = array (5,7,6,8,3,8,2,4,6,10,8,5,6,10,7,6,5,3,7,6);
sort($kids);
$arrlength = count($kids);
$arrayA= array_slice($kids, 0, $arrlength / 2);
$arrayB= array_slice($kids, $arrlength / 2);
Output
// $arrayA
array:10 [▼
0 => 2
1 => 3
2 => 3
3 => 4
4 => 5
5 => 5
6 => 5
7 => 6
8 => 6
9 => 6
]
// $arrayB
array:10 [▼
0 => 6
1 => 6
2 => 7
3 => 7
4 => 7
5 => 8
6 => 8
7 => 8
8 => 10
9 => 10
]
Another approach for achieving what you asked
$kids = array(8,5,6,9,3,8,2,4,6,10,8,5,6,1,7,10,5,3,7,6);
sort($kids);
$teamA = array();
$teamB = array();
foreach($kids as $i => $kid){
if($i % 2){
array_push($teamA, $kid);
} else{
array_push($teamB, $kid);
}
}
It will generate the same output and sum as you want.
This question already has answers here:
How to remove an array value from another array using PHP question
(3 answers)
Closed 2 years ago.
I tried the following code and it should be working, but not getting the required result. What's wrong with the code? I have two arrays and I want to remove the common elements in both arrays so I wore the following code.
<?php
$aMgaMembersList= array (
0 => '9194962',
1 => '9197448',
2 => '9174039',
3 => '9199473',
4 => '9175598',
5 => '9197474',
6 => '9195444',
7 => '9195268',
8 => '9189438',
9 => '9175103',
10 => '9199619',
11 => '9195267',
12 => '9194463',
13 => '9196333',
14 => '9197471',
15 => '9198479',
16 => '9197472',
17 => '9185479',
18 => '9197452',
19 => '9197442',
20 => '9180861',
21 => '9194950',
22 => '9198464',
23 => '9199613',
24 => '9175939',
25 => '9195442',
26 => '9190203',
27 => '9199613',
) ;
$aRocketMembersList = array (
0 => '9174039',
1 => '9175103',
2 => '9175598',
3 => '9175939',
4 => '9180861',
5 => '9185479',
6 => '9189438',
7 => '9190203',
8 => '9194463',
9 => '9194950',
10 => '9194962',
11 => '9195267',
12 => '9195268',
13 => '9195442',
14 => '9195444',
15 => '9196333',
16 => '9197442',
17 => '9197448',
18 => '9197452',
19 => '9197471',
20 => '9197472',
21 => '9197474',
22 => '9198464',
23 => '9198479',
24 => '9199473',
25 => '9199613',
26 => '9199619',
27 => 'arun',
) ;
if (is_array($aRocketMembersList)) {
foreach ($aRocketMembersList as $rocketUsername) {
if (in_array($rocketUsername, $aMgaMembersList)) {
unset($aMgaMembersList[array_search($rocketUsername, $aMgaMembersList)]);
unset($aRocketMembersList[array_search($rocketUsername, $aRocketMembersList)]);
}
}
}
print_r($aRocketMembersList);
print_r($aMgaMembersList);
The out put is
Array
(
[27] => arun
)
Array
(
[27] => 9199613
)
The element 9199613 shouldn't be there. Why it's happening? I ran the code in a different environment and the result is same.
Here's a different function that works regardless of the order of Arrays:
<?php
function different($array1, $array2){
$m = array_merge($array1, $array2); $x = array_intersect($array1, $array2); $a = array_diff($m, $x); $b = array_diff($x, $m); $a = array_merge($a, $b);
$r = [];
foreach($a as $v){
$o = new StdClass; $k = array_search($v, $array1);
if($k === false)$k = array_search($v, $array2);
$o->$k = [$array1[$k], $array2[$k]]; $r[] = $o;
}
return $r;
}
$aMgaMembersList = [
0 => '9194962',
1 => '9197448',
2 => '9174039',
3 => '9199473',
4 => '9175598',
5 => '9197474',
6 => '9195444',
7 => '9195268',
8 => '9189438',
9 => '9175103',
10 => '9199619',
11 => '9195267',
12 => '9194463',
13 => '9196333',
14 => '9197471',
15 => '9198479',
16 => '9197472',
17 => '9185479',
18 => '9197452',
19 => '9197442',
20 => '9180861',
21 => '9194950',
22 => '9198464',
23 => '9199613',
24 => '9175939',
25 => '9195442',
26 => '9190203',
27 => '9199613'
];
$aRocketMembersList = [
0 => '9174039',
1 => '9175103',
2 => '9175598',
3 => '9175939',
4 => '9180861',
5 => '9185479',
6 => '9189438',
7 => '9190203',
8 => '9194463',
9 => '9194950',
10 => '9194962',
11 => '9195267',
12 => '9195268',
13 => '9195442',
14 => '9195444',
15 => '9196333',
16 => '9197442',
17 => '9197448',
18 => '9197452',
19 => '9197471',
20 => '9197472',
21 => '9197474',
22 => '9198464',
23 => '9198479',
24 => '9199473',
25 => '9199613',
26 => '9199619',
27 => 'arun'
];
$diffArray = different($aMgaMembersList, $aRocketMembersList);
$test = json_encode($diffArray);
?>
$tmp1 = array_diff($aMgaMembersList,$aRocketMembersList);
$tmp2 = array_diff($aRocketMembersList,$aMgaMembersList);
$final = array_unqiue(array_merge($tmp1, $tmp2));
unset($tmp1);unset($tmp2);//and maybe original arrays?
There are probably better solutions, but that should work for you. If you had associative arrays instead of numeric values you could exclude array_unqiue
EDIT:
I originally assumed you wanted the results in one array, if that's unnecessary just use the array_diff function twice, and you can maintain your original array names as desired. Again there are probably better solutions (more memory/processor efficient), but in most practical cases this will be fine. If you're working with extremely large data sets... do more research ;)
I have this array built from a function that sorts allowed or valid url slugs and their ids into another array. I can call the current category id by passing the url slug to the category. Now I need to get the children category ids (if any) so i can call the appropriate items from the database for display purpose.
Heres an example of the array:
Array (
[radios] => 1
[radios/motorola] => 2
[radios/motorola/handheld] => 3
[radios/motorola/mobile] => 4
[radios/icom] => 5
[radios/icom/handheld] => 6
[radios/icom/mobile] => 7
[radios/mics-and-speakers] => 8
[radios/mounts] => 9
[radios/radio-other] => 10
[misc] => 11
[misc/led] => 12
[phones] => 13
[phones/samsung] => 14
[phones/lg] => 15
[phones/motorola] => 16
[phones/huawei] => 17
[phones/blackberry] => 18
[phones/flip] => 19
[boosters] => 20
[boosters/standalone] => 21
[boosters/indoor-antenna] => 22
[boosters/outdoor-antenna] => 23
[boosters/connections] => 24
[accessories] => 25
[accessories/cases] => 26
[accessories/other] => 27
[internet] => 28
[internet/fusion] => 29
[internet/point-to-point] => 30
[internet/hotspots] => 31
[internet/gateways] => 32
[internet/switches] => 33
[cameras] => 34
[cameras/complete-kits] => 35
[cameras/additional-cameras] => 36
[cameras/other] => 37
);
As you can see, each result points to the category ID of that group. If i visit the following url:
http://example.com/store/cameras
I can print out that THE PATH CURRENTLY IS: 34 which is correct. Since It has children under it, I also need their ID's and the ID's of any of their children, etc etc. That way on radios, i can show ALL of the sub category items, and on radios/motorola i am only showing the Motorola based items and its children, and such down the line.
If there an easy way, using this array I have now, to sort the children (if any) all the way down and get back just their id's (preferably in a new array) for showing database items?
You might want to create a function like this to filter your array,
function filterArray($array, $term) {
$pattern = "/\b" . str_replace($term, '/', '\/') . "\b/i";
foreach($array as $key => $value) {
if(preg_match($pattern, $key)) {
/* Following condition makes sure that your search
will match starting from the beginning. */
if (stripos(trim($key), $term) === 0){
$filtred[] = $value;
}
}
}
}
Then call the above function with the $array and your search $term.
filterArray($array, 'radios') will give you this,
Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8 [8] => 9 [9] => 10 )
filterArray($array, 'radios/motorola') will give you this,
Array ( [0] => 2 [1] => 3 [2] => 4 )
And so on.. I hope this helps.
You can maybe try double layer array, so that you can store values like this,
Array (
[name] => John
[surname] => Smith
[contact] => Array (
[address] => 18 Maple Street
[number] => 555 477 77 77
)
)
This way if you need to print something from "contact" you can use a loop and print all childs of contact field.
I need to remove a wrong schema from an URL submitted as a string.
I start with this consideration:
The only two allowed schemas are http:// and https://
Starting from this consideration, I need to remove from the string all wrongly formatted schemas like:
htp://example.com
htps://example.com
http:/example.com
https:/example.com
htpexample.com
htps://example.com
http:/example.com
https:/example.com
... many many more ...
My questions are:
Is there a way to calculate all possible variation of wrong schemas?
Which is the best approach to remove them from the given string?
ABOUT QUESTION 2
My first approach would be to create an array with all the wrong schemas and then use something like this:
$wrongSchemas = [/* here all the possible wrong schemas calculated from question 1 */];
$url = str_replace($wrongSchemas, '', $url);
But this approach relies on a correct order, because instead I risk to remove partial schemas and make it wrong anyway.
And anyway I need to find a way to create the array $wrongSchemas!
Any suggestion or any further consideration on the topic that I'm missing, is well appreciated.
use strpos check in your $url
if(strpos($url,"http://")!==0 && strpos($url,"https://")!==0){
//wrong schemas
$exp_string = "";
// $exp_string = strpos($url,"//")?"//":"/";
if(strpos($url,"://"))
$exp_string = "://";
elseif(strpos($url,":/"))
$exp_string = ":/";
elseif(strpos($url,":"))
$exp_string = ":";
elseif(strpos($url,"//"))
$exp_string = "//";
$temp = explode($exp_string,$url);
if(count($temp)>1){
$url = '';
for($i=1;$i<count($temp);$i++){
$url = $url.$temp[$i];
}
//if needed you can add http:// here: $url = 'http://'.$url;
}
}
echo $url;
//process for right schemas
If you need more validations like url starting with ht,htp,etc you can use checkdnsrr or gethostbyname functions to validate domains
After some more thoughts, thanks also to some of your comments (thank you #Frédéric Clausset), I decided that the best approach would be to build the array of wrong schemas on the fly:
$schemas = ['http', 'htp', 'htt', 'ht', 'hp', 'ttp', 'tp'];
$delimiters = ['://', ':/', ':', '//', '/'];
$wrongCombinations = [];
foreach ($schemas as $wrongSchema) {
foreach ($delimiters as $wrongDelimiter) {
$combination = $wrongSchema . $wrongDelimiter;
$combinationSecure = $wrongSchema . 's' . $wrongDelimiter;
if ('http://' !== $combination) {
$wrongCombinations[] = $combination;
}
if ('https://' !== $combinationSecure) {
$wrongCombinations[] = $combinationSecure;
}
}
}
This generates a long array like this:
array:68 [▼
0 => "http:/"
1 => "https:/"
2 => "http:"
3 => "https:"
4 => "http//"
5 => "https//"
6 => "http/"
7 => "https/"
8 => "htp://"
9 => "htps://"
10 => "htp:/"
11 => "htps:/"
12 => "htp:"
13 => "htps:"
14 => "htp//"
15 => "htps//"
16 => "htp/"
17 => "htps/"
18 => "htt://"
19 => "htts://"
20 => "htt:/"
21 => "htts:/"
22 => "htt:"
23 => "htts:"
24 => "htt//"
25 => "htts//"
26 => "htt/"
27 => "htts/"
28 => "ht://"
29 => "hts://"
30 => "ht:/"
31 => "hts:/"
32 => "ht:"
33 => "hts:"
34 => "ht//"
35 => "hts//"
36 => "ht/"
37 => "hts/"
38 => "hp://"
39 => "hps://"
40 => "hp:/"
41 => "hps:/"
42 => "hp:"
43 => "hps:"
44 => "hp//"
45 => "hps//"
46 => "hp/"
47 => "hps/"
48 => "ttp://"
49 => "ttps://"
50 => "ttp:/"
51 => "ttps:/"
52 => "ttp:"
53 => "ttps:"
54 => "ttp//"
55 => "ttps//"
56 => "ttp/"
57 => "ttps/"
58 => "tp://"
59 => "tps://"
60 => "tp:/"
61 => "tps:/"
62 => "tp:"
63 => "tps:"
64 => "tp//"
65 => "tps//"
66 => "tp/"
67 => "tps/"
]
Those 68 combinations are all the possible wrong ones.
Now, a simple str_replace removes the schema if it is one of the wrong ones:
str_replace($combinations, '', $domain);
This intercept wrong URLs like:
htp://example.com > example.com
http:/example.com > example.com
htps:/example.com > example.com
hps:/example.com > example.com
htp:example.com > example.com
many many more
all possible variations
Thank you to all of you for your answers that helped me to better clarify the problem and find my solution! :)
PS
If you find bugs or drawbacks in this code, please, let me know!
I would search for :// if exists in string, after a then a simple in_array with the substring
$url="https://www.example.com";
$validschemas=array("http","https");
$pos=strpos($url,"://");
if($pos)
{
$valid=in_array(substr($url,0,$pos),$validschemas)?true:false;
//If not valid schema, remove schema from url, if it os ok dont touch it.
if(!$valid)
$url=substr($url,$pos+3);
}
else
{
//No schema, then url continues being the same
}
I'm trying to find each missing number in an array like the following.
Array (
[0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 [5] => 6 [6] => 7 [7] => 8
[8] => 9 [9] => 10 [10] => 11 [11] => 12 [12] => 13 [13] => 14 [14] => 15
[15] => 16 [16] => 17 [17] => 18 [18] => 19 [19] => 20 [20] => 21 [21] => 22
[22] => 23 [23] => 24 [24] => 25 [25] => 26 [26] => 27 [27] => 28 [28] => 29
[29] => 30 [30] => 31 [31] => 32 [32] => 33 [33] => 34 [34] => 35 [35] => 36
[36] => 37 [37] => 38 [38] => 39 [39] => 40 [40] => 41 [41] => 42 [42] => 43
[43] => 44 [44] => 45 [45] => 46 [46] => 47 [47] => 48 [48] => 49 [49] => 50
[50] => 51 [51] => 52 [52] => 53 [53] => 54 [54] => 55 [55] => 56 [56] => 57
[57] => 58 [58] => 59 [59] => 60 [60] => 61 [61] => 62 [62] => 63 [63] => 64
[64] => 67 [65] => 68 [66] => 69
)
The numbers 65,66 are missing in this particular array.
My question how do I figure out which numbers are missing with the help of PHP. Specifically what I need to find out is the lowest missing number.
Why: Because then I can assign that number to a member as an id.
You can make use of array_diff and range functions as:
// given array. 3 and 6 are missing.
$arr1 = array(1,2,4,5,7);
// construct a new array:1,2....max(given array).
$arr2 = range(1,max($arr1));
// use array_diff to get the missing elements
$missing = array_diff($arr2,$arr1); // (3,6)
I'm assuming the number is the element, not the key, of the array. I'm also assuming that the numbers start from 1, not 0.
$Expected = 1;
foreach ($InputArray as $Key => $Number)
{
if ($Expected != $Number)
{
break;
}
$Expected++;
}
echo $Number;
For big sorted arrays of unique numbers, you can binary search the array for either the lowest or highest unused number. Cost=Log2N. Example: 65536 items can be searched in 16 loops since
if ( arr[hi] - arr[lo] > hi - lo )
... there are unused numbers in that range ...
So (I don't know PHP, but it can be translated...):
lo = first entry index
hi = last entry index
if ( arr[hi] - arr[lo] == hi - lo )
return arr[hi]+1; // no gaps so return highest + 1
do
{
mid = (lo + hi) / 2;
if ( arr[mid] - arr[lo] > mid - lo ) // there is a gap in the bottom half somewhere
hi = mid; // search the bottom half
else
lo = mid; // search the top half
} while ( hi > lo + 1 ); // search until 2 left
return arr[lo]+1;
If given input is not in sorted order and size of input is very large then we can use following logic in any programming language:
Algorithm
bring smaller chunk into memory from large input
initialize three variables say min = 0, max = 0 and missingIds = []
scan smaller chunked input from left to right
if scannedValue found in missingIds
then,
pop scannedValue from missingIds
go to next value;
If scanned value is near to min
then,
find all the missing numbers between scannedValue and min, push into missingIds
min = scannedValue;
Else if scanned value is near to max
then,
find all the missing numbers between scannedValue and max, push into missingIds
max = scannedValue;
repeat above steps until large input scanned from left to right
Example in PHP
<?php
$largeInput = [40,41,42,43,44,45,1,2,3,4,5,6,7,8,9,10,11,12,13,14,35,36,37,38,39,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,67,68,69,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34];
$missingIds = [];
$min = 0;
$max = 0;
$chunkSize = 10;
$chunkNo = 0;
$currentInput = array_slice($largeInput, $chunkNo, $chunkSize);
while(count($currentInput) > 0) {
foreach($currentInput as $id) {
if(in_array($id,$missingIds)) {
$missingIds = array_diff($missingIds,[$id]);
continue;
}
if($id <= $min) {
$distMin = $min - $id;
if($distMin > 2) {
$tempArr = range($id+1,$min-1);
$missingIds = array_merge($missingIds, $tempArr);
$tempArr = [];
} else if ($distMin > 1) {
$tempArr = [$id+1];
$missingIds = array_merge($missingIds, $tempArr);
$tempArr = [];
}
$min = $id;
} else if ($id >= $max){
$distMax = $id - $max;
if($distMax > 2) {
$tempArr = range($max+1,$id-1);
$missingIds = array_merge($missingIds, $tempArr);
$tempArr = [];
} else if ($distMax > 1) {
$tempArr = [$max+1];
$missingIds = array_merge($missingIds, $tempArr);
$tempArr = [];
}
$max = $id;
}
}
$chunkNo++;
$currentInput = array_slice($largeInput, $chunkNo, $chunkSize);
}
print_r($missingIds);
//$idArrayMissing = array([0] => 1, [1] => 2, [2] => 4, [3] => 5, [4] => 6, [5] => 7);
$idArrayMissing = array(1, 2, 4, 5, 6, 7);
//$idArrayFull = array([0] => 1, [1] => 2, [2] => 3, [3] => 4, [4] => 5, [5] => 6);
$idArrayFull = array(1, 2, 3, 4, 5, 6);
function gap($arr)
{
while (list($k, $v) = each($arr))
if ($k != ($v-1))
return $k;
return -1;
}
print "ok:" . gap($idArrayMissing) . "<br/>\n";
print "full:" . gap($idArrayFull) . "<br/>\n";
The return of the gap function can be 2 values:
-1 could indicate that the array has been traversed and there are no free slots or
$k+1 which could indicate that the first free slot is on the end of the array.
It can also be done easily by using in_array() function like this:
// lets say $InputArray has all the data
// lets declare a variable which we will search inside the $InputArray array and lets initialize it with either 0 or 1 or with the minimum value found inside $InputArray
$start_counting = 1;
$max_value = count($InputArray);
if (!(in_array($start_counting, $InputArray)))
{
echo "Value: ".$start_counting." is missing!"."<br>" ;
}
else{
if($start_counting <= $max_value -1)
{$start_counting++;}
}
else if($start_counting > $max_value -1)
{
echo "All missing numbers printed!"
}
}