I'm searching for an algorithm to remove gaps between numbers. Example of my problem:
Here is a range of integers: [1,2,3,4,9,10,11,17...]
I need to make those numbers like this: [1,2,3,4,5,6,7,8...]
Can anyone provide me with a working example of PHP code to obtain such a result?
You should fetch min and max from an array and create the range,
$min = min($arr);
$max = max($arr);
print_r(range($min,$max));
You can make by using range function as:
// given array 2,4,6 and 9 are missing.
$arr1 = array(1,3,5,7,8,10);
// construct a new array using range function by giving min(given array) and max(given array) value
$arr2 = range(min($arr1),max($arr1));
Related
The following is the code
<?php
$id ="202883-202882-202884-0";
$str = implode('-',array_unique(explode('-', $id)));
echo $str;
?>
The result is
202883-202882-202884-0
for $id ="202883-202882-202882-0";, result is 202883-202882-0
I would like to replace the duplicate value with zero, so that the result should be like 202883-202882-0-0, not just remove it.
and for $id ="202883-0-0-0";, result should be 202883-0-0-0. zero should not be replaced, repeating zeros are allowed.
How can I archive that?
More info:
I want to replace every duplicate numbers. Because this is for a product comparison website. There will be only maximum 4 numbers. each will be either a 6 digit number or single digit zero. all zero means no product was selected. one 6 digit number and 3 zero means, one product selected and 3 blank.
Each 6 digit number will collect data from database, I dont want to allow users to enter same number multiple times (will happen only if the number is add with the URL manually.).
Update: I understand that my question was not clear, may be my English is poor.
Here is more explanation, this function is for a smartphone comparison website.
The URL format is sitename.com/compare.html?id=202883-202882-202889-202888.
All three numbers are different smartphones(their database product ID).
I dont want to let users to type in the same product ID like id=202883-202882-202882-202888. It will not display two 202882 results in the website, but it will cause some small issues. The URL will be same without change, but the internal PHP code should consider it as id=202883-202882-202888-0.
The duplicates should be replaced as zero and added to the end.
There will be only 4 numbers separated by "-".
The following examples might clear the cloud!
if pid=202883-202882-202889-202888 the result should be 202883-202882-202889-202888
if pid=202883-202883-202883-202888 the result should be 202888-0-0-0
if pid=202883-202882-202883-202888 the result should be 202883-202882-202888-0
if pid=202882-202882-202882-202882 the result should be 202882-0-0-0
I want to allow only either 6 digit numbers or single digit zero through the string.
if pid=rgfsdg-fgsdfr4354-202883-0 the result should be 202883-0-0-0
if pid=fasdfasd-asdfads-adsfds-dasfad the result should be 0-0-0-0
if pid=4354-45882-445202882-202882 the result should be 202882-0-0-0
It is too complicated for me create, I know there are bright minds out there who can do it much more efficiently than I can.
You can do a array_unique (preserves key), then fill the gaps with 0. Sort by key and you are done :)
+ on arrays will unify the arrays but prioritizes the one on the left.
Code
$input = "0-1-1-3-1-1-3-5-0";
$array = explode('-', $input);
$result = array_unique($array) + array_fill(0, count($array), 0);
ksort($result);
var_dump(implode('-',$result));
Code (v2 - suggested by mickmackusa) - shorter and easier to understand
Fill an array of the size of the input array. And replace by leftover values from array_unique. No ksort needed. 0s will be replaced at the preserved keys of array_unique.
$input = "0-1-1-3-1-1-3-5-0";
$array = explode('-', $input);
$result = array_replace(array_fill(0, count($array), 0), array_unique($array));
var_export($result);
Working example.
Output
string(17) "0-1-0-3-0-0-0-5-0"
Working example.
references
ksort - sort by key
array_fill - generate an array filled with 0 of a certain length
This is another way to do it.
$id = "202883-202882-202882-0-234567-2-2-45435";
From the String you explode the string into an array based on the delimiter which in this case is '-'/
$id_array = explode('-', $id);
Then we can loop through the array and for every unique entry we find, we can store it in another array. Thus we are building an array as we search through the array.
$id_array_temp = [];
// Loop through the array
foreach ($id_array as $value) {
if ( in_array($value, $id_array_temp)) {
// If the entry exists, replace it with a 0
$id_array_temp[] = 0;
} else {
// If the entry does not exist, save the value so we can inspect it on the next loop.
$id_array_temp[] = $value;
}
}
At the end of this operation we will have an array of unique values with any duplicates replaced with a 0.
To recreate the string, we can use implode...
$str = implode('-', $id_array_temp);
echo $str;
Refactoring this, using a ternary to replace the If,else...
$id_array = explode('-', $id);
$id_array_temp = [];
foreach ($id_array as $value) {
$id_array_temp[] = in_array($value, $id_array_temp) ? 0 : $value;
}
$str = implode('-', $id_array_temp);
echo $str;
Output is
202883-202882-0-0-234567-2-0-45435
This appears to be a classic XY Problem.
The essential actions only need to be:
Separate the substrings in the hyphen delimited string.
Validate that the characters in each substring are in the correct format AND are unique to the set.
Only take meaningful action on qualifying value.
You see, there is no benefit to replacing/sanitizing anything when you only really need to validate the input data. Adding zeros to your input just creates more work later.
In short, you should use a direct approach similar to this flow:
if (!empty($_GET['id'])) {
$ids = array_unique(explode('-', $_GET['id']));
foreach ($ids as $id) {
if (ctype_digit($id) && strlen($id) === 6) {
// or: if (preg_match('~^\d{6}$~', $id)) {
takeYourNecessaryAction($id);
}
}
}
At the moment my "method" checks if the array_key is in the array, i need to add that if the key length is 13 it is okay, but when it is longer it has to delete the like first 5 numbers of the list. My code searches the price according to my key out of the database, and compares it to a list where the "keys" are a bit different. So to make it easier to understand:
The key in my database is: 2840529503100
The key in the table where i have to get the price from is: 000002840529503100
So what i basically need to do is get a substring from the "list" or "table" which takes the last 13 numbers because the right keys of my database are always 13 numbers long.
$teile = array();
while ($dbRow = $sqlres->fetch_assoc()) {
$teile[$dbRow['nummer']] = $dbRow;
if (array_key_exists($fileRow[0], $teile)) {
If your first five 0 values is constant means you can use substr() like this:
$str = '000002840529503100';
echo $str2 = substr($str, 5);
Another method for substr() is only keep the last last 13 digits like this:
$str = '000002840529503100';
echo $str2 = substr($str, -13);
Else to remove the first 0 values you can use ltrim() like this:
echo ltrim('000002840529503100', '0');
Note: without quotes these two functions won't work.
As an alternative to Nawins solution you can also use PHP Typecasting to automatically remove the leading zeros.
NOTE: for my example; I can't see which variable you're trying to change. But assumed the first...
Thus:
$fileRow[0] = "000002840529503100"
(int)$fileRow[0] = "2840529503100";
This would make:
if (array_key_exists((int)$fileRow[0], $teile)) {
...
}
BEWARE:
This example doesn't change the stored value of $fileRow[0] so using it as a future key reference (~print $array[$fileRow[0]]) will still use the longer number until the (int) version has been set as the variable/key value, example:
$fileRow[0] = (int)$fileRow[0];
Looking the function below:
function CustomShuffle($arr, $para){
............................
............................
return $array;
}
Suppose this is an array:
$array = array("red","green","blue","yellow","purple");
looking output something like below (May be different ordered but must be same for same integer parameter)
$result = CustomShuffle($array, 10);
// output: array("blue","purple","yellow","red","green") same
$result = CustomShuffle($array, 12);
// output: array("purple","yellow","red","green","blue")
$result = CustomShuffle($array, 10);
// output: array("blue","purple","yellow","red","green") same
$result = CustomShuffle($array, 7);
// output: array("blue","yellow","purple","red","green")
Simply, array will be shuffled with respect to integer parameter but output will be same for same parameter. Is it possible?
Yes this is possible, how it happens does come down to a desired implementation and how many permutations you wish to allow. A very naive method of accomplishing this is to have a loop that runs $para times within CustomShuffle that would array_shift() an element then array_push() that same element. This method would only give you count($array) possible outcomes, meaning numbers congruent modulo count($array) would produce the same result.
The optimal algorithm would allow you to take advantage of the maximum combinations, which would be gmp_fact(count($array)), or simply the factorial of the length of the input array. There is no possible way to achieve more unique combinations than this value, so no matter what algorithm you design, you will always have a constraint on the value of $para until you eventually encounter a combination already seen.
So I make an API call. This generates an array with dynamic number of elements. I want to add additional empty keys until the number of elements reach 50 (api call will always be lesser than 50). What is the easiest way to do this? Currently I am doing:
$dataArray = $this->APICall();
$toAdd = 50 - count($dataArray);
for($x=$toAdd;$x<=50;$x++)
{
$dataArray[$x] = "";
}
I wanted to check if there is an easier, perhaps single-line way of doing this...
There is function array_fill that you can use to fill array with spaces to size of 50. And then merge it with initial array.
Documentation for array_fill is here
$dataArray = array_merge($dataArray, array_fill(count($dataArray), 50 - count($dataArray), ""));
It's a simple question, but searching here I found different variations, but not really what I need. So:
Say I have array of numbers: [1,4,5,7,9]
What I need is an inverted result set of numbers up to max 10: [2,3,6,8,10]
$initialArray = array(1,4,5,7,9);
$requiredRange = range(1,10);
$invertedArray = array_diff($requiredRange,$initialArray);