How to get minimum positive value greater then 0 in php - php

Question

I want to find minimum value from an array and subtract that value from all the elements until all the elements becomes 0. The problem is that if the array contains one of the element as 0 then it doesn't reflect anything. Thanks in advance.
<?php
$handle = fopen ("php://stdin","r");
fscanf($handle,"%d",$n);
$arr_temp = fgets($handle);
$arr = explode(" ",$arr_temp);
array_walk($arr,'intval');
for($j=0;$j<10;$j++)
{
$min = min($arr);
for($i=0;$i<count($arr);$i++)
{
if($arr[$i]>=$min)
$arr[$i]-=$min;
echo $arr[$i]." ";
}
echo "\n";
}
?>

Answer 1

Using array_filter(), plus a function you can get the minimum positive non-zero integer even if an array contains elements whose value is zero, as follows:
<?php
$arr = array(0, 1, 2, 3, 4, 0, 5, 6, 4, 3, 2, 1,0);
function getMin( $a ) {
$arr_filtered = array_values(array_filter( $a ));
return min($arr_filtered);
}
$min = getMin( $arr );
$count = count($arr);
while( count( array_unique($arr) ) > 1 ) {
for( $i = 0; $i < $count; $i++)
{
if( $arr[$i] >= $min ){
$arr[$i] -= $min;
echo $arr[$i]." ";
}
}
echo "\n";
}
See demo
Note, the code re-indexes the filtered array in getMin() by using array_values().
As long as the minimum value is one the above script works well. However, if the minimum value were another number, then the code needs to be adjusted. The following script handles a multi-dimensional array composed of four arrays, each with a different minimum value, including one with negative values:
<?php
error_reporting(E_ALL);
$a = [ [0,1, 2, 3, 4, 0, 5, 6, 4, 3, 2, 1,0],
[0, 2, 3, 4, 0, 5, 6, 4, 3, 2, 0],
[0, 3, 4, 0, 5, 6, 7,8,4, 3, 0],
[-1,0,1,2,3,4,2,1,0,-1]
];
function getMin( $a ) {
return min($a);
}
foreach ($a as $arr) {
while( ( $arr != null ) ) {
$arr = array_values(array_filter($arr));
if ($arr == null) {
break;
}
$min = getMin( $arr );
foreach ($arr as &$e) {
$e -= $min;
}
unset($e);
echo join(" ",$arr),"\n";
}
echo "\n";
}
see demo
Note, the second script explicitly filters out the zero values in each array whereas the first script effectively does so. The primary difference between the two scripts is that getMin() needs to be in the while loop so that the subtraction correctly occurs when the minimum number is greater than one or is a negative number.
The script also simplifies the code in several ways. Much more simple condition for the while loop -- works as long as array is not null. The code no longer needs getCount() since I changed the subtraction loop to use a foreach with a reference variable which is subsequently unset -- important to do to avoid problems. This foreach loop also does not require the if conditional of the first script.

Answer 2

It is because you taking each and every time $min = min($arr); value and it became 0 thats why your code is not working.
try below code
$min = min($arr);
for($j=0;$j<=100;$j++)
{
if (count(array_unique($arr)) === 1 && end($arr) === 0) {
break;
}
for($i=0;$i<count($arr);$i++)
{
if($arr[$i] >= $min){
$arr[$i]-=$min;
echo $arr[$i]." ";
}
}
echo "<br>";
}

Answer 3

I do not know much about php but in the first for loop you should check the elements of the array if they are zero or not using if statements e.g if(arr[j]!=0)
for($j=0;$j<10;$j++)
{
if($arr[$j]!=$0)
$min = min($arr);
for($i=0;$i<count($arr);$i++)
{
if($arr[$i]>=$min)
$arr[$i]-=$min;
echo $arr[$i]." ";
}
echo "\n";
}