Sorry for my bad English and thanks for your help in advance! I have kind of a tricky problem I've encountered while coding. Here's the point:
I need a script that essentially extracts the 5 max values of 5 arrays, that are "mixed", i.e. they contain "recurrent" values. Here is an example:
array1(a, b)
array2(a, c, d, e, g)
array3(b, d, g, h)
array4(e, t, z)
array5(b, c, d, k)
The 2 essential requests are:
1) the sum of those 5 arrays (array1+array2+array3...) MUST be the highest possible...
2) ...without repeat ANY value previously used** (e.g. if in array1 the top value was "b", this cannot be re-used as max value in arrays 3 or 5).
Currently I have this...:
$group1 = array(a, b);
$group = array(a, b, c, d);
$max1a = max(group1);
$max2a = max(group2) unset($max1a);
$sum1 = $max1a + $max2a;
$max2b = max(group2);
$max1b = max(group1)
unset($max2b);
$sum2 = $max1b + $max2b;
if($sum1 > $sum2) {
echo $sum1
} else {
echo $sum2
}
... but it's kinda impossible to use this code with 5 arrays, because I should compare 5! (120...!!!) combinations in order to find the max sum value.
I know the problem is quite difficult to explain and to solve, but I really need your help and I hope you can save me!!!
Cheers
I'm adding this as another answer to leave the previous one intact for someone coming across this looking for that variation on this behaviour.
Given the 2 arrays:
$array1 = array(30, 29, 20);
$array2 = array(30, 20, 10);
The maximum sum using one element from each is 59 - this is dramatically different to my previous approach (and the answers' of others) which took the max element of the first array and then the highest element of the next array that is not equal to any previously used value - this would give 50 instead.
The code you want is this:
$mainArray = array();
$mainArray[] = array(30, 29, 20);
$mainArray[] = array(30, 20, 10);
$tempArray = array();
$newArray = array();
foreach($mainArray as $innerArray) {
$newArray = array();
if (count($tempArray) == 0) {
foreach ($innerArray as $value) {
$newArray[] = array('total' => $value, 'used' => array($value));
}
}
else {
foreach ($tempArray as $key => $innerTempArray) {
$placed = FALSE;
foreach ($innerArray as $value) {
if (!(in_array($value, $innerTempArray['used']))) {
$newArray[] = array('total' => $tempArray[$key]['total'] + $value, 'used' => $tempArray[$key]['used']);
$newArray[count($newArray) - 1]['used'][] = $value;
$placed = TRUE;
}
}
if (!($placed)) {
echo "An array had no elements that had not already been used";
die();
}
}
}
$tempArray = $newArray;
}
$total = 0;
if (count($newArray) == 0) {
echo "No data passed";
die();
}
else {
$total = $newArray[0]['total'];
}
for ($i = 0; $i < count($newArray); $i++) {
if ($newArray[$i]['total'] > $total) {
$total = $newArray[$i]['total'];
}
}
var_dump($total);
EDIT - Do not repeat used variables (but repeated values are ok):
Let
//$a = 30, $b = 30, $c = 25, $d = 20, $e = 19
$array1 = array($a, $c, $d);
$array2 = array($b, $d, $e);
We want to choose $a from $array1 and $b from $array2 as these give the largest sum - although they're values are the same that is allowed because we only care if the names of the variables saved to that place are the same.
With the arrays in the above format there is no way of achieving the desired behaviour - the arrays do not know what the name of the variable who's value was assigned to their elements, only it's value. Therefore we must change the first part of the original answer to:
$mainArray[] = array('a', 'c', 'd');
$mainArray[] = array('b', 'd', 'e');
and also have either the of the following before the first foreach loop (to declare $a, $b, $c, $d, $e)
//either
extract(array(
'a' => 30,
'b' => 30,
'c' => 25,
'd' => 20,
'e' => 19
));
//or
$a = 30; $b = 30; $c = 25; $d = 20; $e = 19;
The above both do exactly the same thing, I just prefer the first for neatness.
Then replace the line below
$newArray[] = array('total' => $value, 'used' => array($value));
with
$newArray[] = array('total' => ${$value}, 'used' => array($value));
The change is curly brackets around the first $value because that is then evaluated to get the variable name to use (like below example):
$test = 'hello';
$var = 'test';
echo ${$var}; //prints 'hello'
A similar change replaces
$newArray[] = array('total' => $tempArray[$key]['total'] + $value, 'used' => $tempArray[$key]['used']);
with
$newArray[] = array('total' => $tempArray[$key]['total'] + ${$value}, 'used' => $tempArray[$key]['used']);
Now the code will function as wanted :)
If you are dynamically building the arrays you are comparing and can't build the array of strings instead of variables then there is no way to do it. You would need some way of extracting "$a" or "a" from $a = 30, which PHP is not meant to do (there are hacks but they are complicated and only work in certain situations (google "get variable name as string in php" to see what I mean)
If by the top value you mean the first alphabetically then the following would work:
$array1 = array('a', 'b');
$array2 = array('a', 'c', 'd', 'e', 'g');
$array3 = array('b', 'd', 'g', 'h');
$array4 = array('e', 't', 'z');
$array5 = array('b', 'c', 'd', 'k');
$mainArray = array($array1, $array2, $array3, $array4, $array5);
foreach ($mainArray as $key => $value) {
sort($mainArray[$key]);
}
$resultArray = array();
foreach($maniArray as $key1 => $value1) {
$placed = FALSE;
foreach ($value1 as $value2) {
if (!(in_array($value2, $resultArray))) {
$resultArray[] = $value2;
$placed = TRUE;
break;
}
}
if (!($placed)) {
echo "All the values in the " . ($key + 1) . "th array are already max values in other arrays";
die();
}
}
var_dump($resultArray);
I'm not sure, of i really understood your problem correctly, these are my assumptions:
You have five arrays containing numbers
These numbers can occur multiple times across the arrays
You want to find the highest possible sum of elements across your arrays
The sum uses one single value of each array
But the sum must not use the same number twice
Is that correct?
If Yes, then:
The highest possible sum across all arrays is always the sum of the largest elements. If you do not want to use the same number twice, you can just get the maximum from the first array, remove it from all the others and then sum up all the remaining maxima.
Like so:
$arrays = array();
$arrays[] = array(1, 2);
$arrays[] = array(1, 3, 4, 5, 7);
$arrays[] = array(2, 4, 7, 8);
$arrays[] = array(5, 20, 26);
$arrays[] = array(2, 3, 4, 11);
for($i=0, $n=count($arrays); $i<$n; $i++) {
if($i===0) {
$a1max = max($arrays[$i]);
$sum = $a1max;
} else {
$duplicate_pos = array_search($a1max, $arrays[$i]);
if($duplicate_pos !== FALSE) {
unset($arrays[$i][$duplicate_pos]);
}
$sum += max($arrays[$i]);
}
}
echo "sum: " . $sum . "\n";
Assuming you have grouped together all your values in one array like this,
$array = array(
array(1,2,3),
array(1,2,3,4),
array(1,2,3,4,5,6),
array(1,2,3,4,5,6),
array(1,2,3,4,5,6,7)
);
Loop through $array, and get the highest value which has not been used previously,
$max = array();
foreach($array as $value)
$max[] = max(array_diff($value, $max));
Calculate the sum of all values with array_sum(),
echo "The maximal sum is: ".array_sum($max);
Related
I have a code like this:
Lets assume that this arrays has this values:
$arr1 = array();
$arr2 = array();
$result = array();
$arr1[] = array( 'grade' => [1,2,3,4] );
$arr2[] = array( 'grade' => [1,2,3,4] );
foreach($arr1 as $a1){
$set1 = $a1['grade'];
foreach($arr2 as $a2){
$set2 = $a2['grade'];
}
$result[] = array('show_result' => $set1+$set2);
}
foreach{$result as $res){
echo $res['show_result'];
}
The output of the array $res['show_result'] must be:
2, 4, 6, 8
But I get the wrong addition of this arrays. Help will be much appreciated.
As Joni said, your first error is on line 3: ' should be ;
Then, you're not filling arrays like you wanted : array( 'grade' => 1,2,3,4 ); creates an array with first key is 'grade' with value '1', then second key is '0' with value '2' etc...
Your last foreach loop has a syntax error similar to your first error.
See a working correction here
$arr1 = array();
$arr2 = array();
$result = array();
array_push($arr1, 1, 2, 3, 4); //fill array with 4 values (integers)
array_push($arr2, 1, 2, 3, 4); //fill array with 4 values (integers)
//so $arr1 & $arr2 are now a 4 elements arrays
$length = count($arr1); //size of array, here 4
for ($i = 0; $i < $length; $i++) { //loop over arrays
array_push($result, ($arr1[$i] + $arr2[$i])); //fill the results array with sum of the values from the same position
}
var_dump($result);
You have quite a few syntax errors in your code.
Although this solution works, the idea behind using the same counter, $i, to extract a value from both arrays is brittle. For example, you'll get an Undefined offset if the first array has 5 grades instead of 4. If you take a step back and explain your problem in the larger context, perhaps we can provide a better solution. I get the sneaking suspicion you're asking an XY Problem.
http://sandbox.onlinephpfunctions.com/code/bb4f492c183fcde1cf4edd50de7ceebf19fe343a
<?php
$gradeList1 = ['grade' => [1,2,3,4]];
$gradeList2 = ['grade' => [1,2,3,4]];
$result = [];
for ($i = 0; $i < count($gradeList1['grade']); $i++) {
$first = $gradeList1['grade'][$i];
$second = $gradeList2['grade'][$i];
$result['show_result'][] = (int)$first + (int)$second;
}
var_dump($result);
I have 4 variables and each of those have an integer assigned to them. Could anybody please let me know how I can get the name of the variable which has the second smallest value?
Thanks.
Use compact to set the variables to one array, sort the array, then use array slice to get the second value.
Then optionally echo the key of the second value.
$a = 2;
$b = 7;
$c = 6;
$d = 1;
$arr = compact('a', 'b', 'c', 'd');
asort($arr);
$second = array_slice($arr,1,1);
Echo "variable name " . Key($second) ."\n";
Echo "value " . ${key($second)};
https://3v4l.org/SVdCq
Updated the code with how to access the original variable from the array
Unless you have a structured way of naming your variables eg prefix_x there is no real way.
Recommended way is using an array like this:
$array = array(
"a" => 3,
"b" => 2,
"c" => 1,
"d" => 6
);
// Sort the array descending but keep the keys.
// http://php.net/manual/en/function.asort.php.
asort($array);
// Fetch the keys and get the second item (index 1).
// This is the key you are looking for per your question.
$second_key = array_keys($array)[1];
// Dumping the result to show it's the second lowest value.
var_dump($array[$second_key]); // int(2).
To be more in line with your question you can create your array like this.
$array = array();
$array['variable_one'] = $variable_one;
$array['some_random_var'] = $some_random_var;
$array['foo'] = $foo;
$array['bar']= $bar;
// Same code as above here.
Instead of using 4 variables for 4 integer values, you can use an array to store these values. Sort the array and print the second index of the array i.e. 1.
<?php
$x = array(2,3,1,6);
$i = 0, $j = 0, $temp = 0;
for($i = 0; $i < 4; $i++){
for($j=0; $j < 4 - $i; j++){
if($x[$j] > $x[$j+1]){
$temp = $x[$j];
$x[$j] = $x[$j+1];
$x[$j+1] = $temp;
}
}
}
for($j = 0; $j < 4; $j++){
echo $x[$j];
}
echo $x[1];
?>
First you need to have all Variables in an Array. You can do this this way:
$array = array(
'a' => 3,
'b' => 6,
'c' => 2,
'd' => 1
);
or this way:
$array['a'] = 3;
$array['b'] = 6;
// etc
Then you need to sort the Items with natsort() to receive a natural Sorting.
natsort($array);
Then you flip the Array-Keys with the Values (In Case you want the Value, skip this Line)
$array = array_flip($array);
After this you jump to the next Item in the Array (Position 1) by using next();
echo next($array);
Makes in Total a pretty short Script:
$array = array(
'a' => 3,
'b' => 6,
'c' => 2,
'd' => 1
);
natsort($array);
$array = array_flip($array);
echo next($array);
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";
}
?>
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.
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>";
}
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";
}
I have an array. I'd like to get the three highest values of the array, but also remember which part of the array it was in.
For example, if my array is [12,3,7,19,24], my result should be values 24,19,12, at locations 4, 0, 3.
How do I do that? The first part is easy. Getting the locations is difficult.
Secondly, I'd like to also use the top three OR top number after three, if some are tied. So, for example, if I have [18,18,17,17,4], I'd like to display 18, 18, 17, and 17, at location 0,1,2,3.
Does that make sense? Is there an easy way to do that?
Wouldn't you be there using asort()?
For example:
<?php
$list = [4,18,18,17,17];
// Sort maintaining indexes.
asort($list);
// Slice the first 3 elements from the array.
$top3 = array_slice($list, -3, null, true);
// Results in: [ 1 => 18, 2 => 18, 3 => 17 ]
Or you can use arsort
function getMyTop($list, $offset, $top) {
arsort($list);
return array_slice($list, $offset, $top, true);
}
$myTop = getMyTop($list, 0, 3);
$myNextTop = getMyTop($list, 3, 4);
This is what you need!
<?php
$array = array(12,3,7,19,24);
$array_processed = array();
$highest_index = 0;
while($highest_index < 3)
{
$max = max($array);
$index = array_search($max,$array);
$array_processed[$index] = $max;
unset($array[$index]);
$highest_index++;
}
print_r($array_processed);
?>
You will get Index as well as the value! You just have to define how many top values you want! Let me know if it's what you want!
function top_three_positions($array){
// Sort the array from max to min
arsort($array);
// Unset everything in sorted array after the first three elements
$count = 0;
foreach($array as $key => $ar){
if($count > 2){
unset($array[$key]);
}
$count++;
}
// Return array with top 3 values with their indexes preserved.
return $array;
}
You can use a loop to determine how many elements your top-three-with-ties will have, after applying arsort:
function getTop($arr, $num = 3) {
arsort($arr);
foreach(array_values($arr) as $i => $v) {
if ($i >= $num && $v !== $prev) return array_slice($arr, 0, $i, true);
$prev = $v;
}
return $arr;
}
// Sample input
$arr = [4,18,17,6,17,18,9];
$top = getTop($arr, 3);
print_r($top); // [5 => 18, 1 => 18, 4 => 17, 2 => 17]
try this:
public function getTopSortedThree(array $data, $n = 3, $asc = true)
{
if ($asc) {
uasort($data, function ($a, $b) { return $a>$b;});
} else {
uasort($data, function ($a, $b) { return $a<$b;});
}
$count = 0;
$result = [];
foreach ($data as $key => $value) {
$result[] = $data[$key];
$count++;
if ($count >= $n){
break;
}
}
return $result;
}
Send false for desc order and nothing for asc order
Send $n with number of top values you want.
This functionality doesn't losing keys.
This task merely calls for a descending sort, retention of the top three values, and in the case of values after the third-positioned value being equal to the third value, retain these as well.
After calling rsort(), call a for() loop starting from the fourth element ([3]). If the current value is not equal to the value in the third position, stop iterating, and isolate the elements from the front of the array to the previous iteration's index. Done.
p.s. If the input array has 3 or fewer elements, the for() loop is never entered and the whole (short) array avoids truncation after being sorted.
Code: (Demo)
$array = [18, 17, 4, 18, 17, 16, 17];
rsort($array);
for ($i = 3, $count = count($array); $i < $count; ++$i) {
if ($array[2] != $array[$i]) {
$array = array_slice($array, 0, $i);
break;
}
}
var_export($array);
Because the loop purely finds the appropriate finishing point of the array ($i), this could also be compacted to: (Demo)
rsort($array);
for ($i = 3, $count = count($array); $i < $count && $array[2] === $array[$i]; ++$i);
var_export(array_slice($array, 0, $i));
Or slightly reduced further to: (Demo)
rsort($array);
for ($i = 3; isset($array[2], $array[$i]) && $array[2] === $array[$i]; ++$i);
var_export(array_slice($array, 0, $i));
Output:
array (
0 => 18,
1 => 18,
2 => 17,
3 => 17,
4 => 17,
)
I'v written 2 codes to shuffle some arrays whitch are in a for loop
First:
$numbers = range(0, sizeof($array_id)-1);
shuffle($numbers);
foreach ($numbers as $number) {
$arr = array("user" => array("id" => $array_id[$number], "name" => $array_name[$number], "key" => $array_key[$number]));
}
echo json_encode($arr);
This one has a big problem and that's if the $number in one of the arrays equals to 5 it won't loop to put another result of $number in the that array, for example the result would be something like this:
{"user":{"id":["18","2","36"],"name":["alex","john"],"key":["159","228,"486,"852"]]}}
All of my arrays have 5 values in them and you can see it returned them defectively.I'll be thankful if anyone can tell me why when $number gets the max value in range by shuffle and array gets that $number it stocks?
Second:
function shuffle_assoc(&$array) {
if (shuffle($array)) {
return $array;
}else{
return FALSE;
}
}
for ($y=0; $y<sizeof($array_id); $y++) {
$arr = array("user" => array("id" => shuffle_assoc($array_id), "name" => shuffle_assoc($array_name), "key" => shuffle_assoc($array_key)));
}
echo json_encode($arr);
This one works fine But I want the id and name to be match I mean they shuffle the same(if $array_id[2] then array_name[2]) that's why I wrote the first code.anyway for this one if anyone knows how to make id and name shuffle the same I'll be appreciate that.(sorry if I had mistakes in my writing my first language isn't English but I love English :)
I'm not sure that I completely understood you, but
$numbers = range(0, 5);
// $number = array(0, 1, 2, 3, 4, 5)
All of my arrays have 5 values
It's
$array_id[0]
$array_id[1]
$array_id[2]
$array_id[3]
$array_id[4]
So you haven't $array_id[5]. I think you need $numbers = range(0, 4);
EDIT:
Once again, I'm not sure if you want this to happen.
<?php
$array_id = array(1,2,3,4,5);
$array_name = array('a','b','c','d','e');
$numbers = range(0, 4);
shuffle($numbers);
$arr = array();
foreach ($numbers as $number) {
$arr["id"][] = $array_id[$number];
$arr["name"][] = $array_name[$number];
}
$arr2 = array("user" => array("id" => $arr["id"], "name" => $arr["name"]));
echo json_encode($arr2);
?>