I have this snippet where I am trying to generate array of array of array of random numbers.
function generateRandomNumbers($pACount, $pBCount, $pCCount, $pDCount) {
$points = array();
$score = array();
$res = array();
$val = array();
for ($i = 0; $i <= $pACount; $i++) {
for ($j = 0; $j <= $pBCount; $i++) {
for ($k = 0; $k <= $pCCount; $i++) {
for ($l = 0; $l <= $pDCount; $i++) {
$points[] = rand(5, 95);
}
$score[] = $points;
}
$res[] = $score;
}
$val[] = $res;
}
return $val;
}
When I return this to AJAX it is returned as: [[[[5, 32, 73, 62, 45]]]]
which was suppose to be
[[[[5, 32, 73, 62, 45], [15, 2, 7, 6, 50]],[[25, 52, 93, 2, 5], [16, 32, 67, 63, 15]]]]
I am reletively very new to php coding(started a week back) and I have no clue here.
What am I missing?
You are using $i++ in every for loop, while it was supposed to be $j++, $k++ and $l++.
The corrected code
function generateRandomNumbers($pACount, $pBCount, $pCCount, $pDCount) {
$points = array();
$score = array();
$res = array();
$val = array();
for ($i = 0; $i <= $pACount; $i++) {
for ($j = 0; $j <= $pBCount; $j++) {
for ($k = 0; $k <= $pCCount; $k++) {
for ($l = 0; $l <= $pDCount; $l++) {
$points[] = rand(5, 95);
}
$score[] = $points;
}
$res[] = $score;
}
$val[] = $res;
}
return $val;
}
Related
So I have an array of integers: <1, 2, 3, 9, 10, 11, 14>, that I would like to join together in this format: <1-3, 9-11, 14>.
I'm new to PHP and tried doing this by looping through the array:
function pasteTogether($val)
{
$newVals = array();
$min = $val[0];
$max = $val[1];
$counter = 0;
for ($i = 0; $i < count($val); $i++)
{
if ($val[$i + 1] === $val[$i] + 1)
{
$max = $val[$i + 1];
}
else
{
$tempVal = $min."-".$max;
$newVals[$counter] = $tempVal;
$counter++;
$min = $val[$i];
}
}
return $newVals;
}
However, when I run this code, I get <1-3, 3-11, 11-11, 14-14>
PHP Fatal error: Maximum execution time of 30 seconds exceeded in ../learning.php on line 36
Because the for loop never ends you increment $val instead of $i
$array = array(1, 2, 3, 9, 10, 11, 14);
function pasteTogether($val)
{
$newVals = array();
$min = $val[0];
$max = $val[1];
$counter = 0;
for ($i = 0; $i < count($val); $i++)
{
if ($val[$i + 1] === $val[$i] + 1)
{
$max = $val[$i + 1];
}
else
{
$tempVal = $min."-".$max;
$newVals[$counter] = $tempVal;
$counter++;
$min = $val[$i];
}
}
return $newVals;
}
pasteTogether($array);
I have been playing around with this interesting problem and found another solution. So, if anyone is interested:
$arr=array(1, 2, 3, 9, 10, 11, 14, 15, 16, 18);
$v0=$dif=null;$rows=array();
foreach ($arr as $i => $v) {
if ($dif!=($d=($v-$i))){
if ($v0) $rows[]="$v0-".$arr[$i-1];
$v0=$v;
$dif=$d;
}
}
$rows[]="$v0-".($d==$dif?$arr[$i]:$v0);
print_r($rows);
I added a few numbers to the array and the result is this:
$rows = Array
(
[0] => 1-3
[1] => 9-11
[2] => 14-16
[3] => 18-18
)
You can find a little demo here: http://rextester.com/ABC25608
This works:
function pasteTogether($val)
{
$compacted = [];
$min = null;
$max = null;
$format = function ($a, $b) {
return ($a < $b ? "$a-$b" : $a);
};
foreach ($val as $current) {
if ($min === null) {
$min = $current;
$max = $current - 1;
}
if ($current == $max + 1) {
$max++;
} else {
$compacted[] = $format($min, $max);
$min = $current;
$max = $current;
}
}
$compacted[] = $format($min, $max);
return $compacted;
}
echo '<', implode(', ', pasteTogether([1, 2, 3, 9, 10, 11, 14])), '>';
Output:
<1-3, 9-11, 14>
I am currently calculating diagonal for n x n square matrix. I can able to calculate Primary diagonal with below code.
function calculateDiagonal($array) {
$length = count($array);
$primary = 0;
$secondary = 0;
for ($i = 0; $i < $length; $i++):
for ($j = 0; $j < $length; $j++):
if ($i == $j):
$primary += $array[$i][$j];
endif;
endfor;
endfor;
$totalSum = $primary + $secondary;
return $totalSum;
}
Can anyone help me to calculate sum of secondary diagonal.
check this as a reference.
Please try with this. You can do sum of diagonal with minimum iteration.
$a = [ [1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12], [13, 14, 15, 16]];
$n = 4;//nxn matrix
$d = $s = 0; //initialize both diagonal sum to 0
for ($i = 0; $i < $n; $i++) {
$d += $a[$i][$i];
$s += $a[$i][$n - $i - 1];
}
var_dump($d);//primary diagonal total
var_dump($s);//secondary diagonal total
Try this
function calculate2Diagonal($array) {
$length = count($array)-1;
$primary = 0;
$secondary = 0;
echo $length;
for ($i = $length; $i >= 0; $i--):
for ($j = $length; $j >=0; $j--):
if ($i == $j):
$primary += $array[$i][$j];
endif;
endfor;
endfor;
$totalSum = $primary + $secondary;
return $totalSum;
}
Only a for inverse ;)
Just using the function array_reduce:
function diagonalSum($arr) {
$i = 0;
$n = count($arr);
return array_reduce($arr,
function ($c, $str) use (&$i, $n ) {
$i++;
return $c + $str[$i-1] + $str[$n-$i];
}, 0);
}
demo
Please help
when i want yo remove an element from array buu after when i print array it shows error
4
6
2
NOTICE Undefined offset: 3 on line number 16
<?php
$value = 22;
$numbers = array(4, 6, 2, 22, 11);
$arrlength = count($numbers);
for($y = 0; $y < $arrlength ; $y++) {
if ( $numbers[$y] == $value) {
unset($numbers[$y]);
}
}
$arrlength = count($numbers);
for($x = 0; $x < $arrlength; $x++) {
echo $numbers[$x];
echo "<br>";
}
?>
You should use "array_values()" to re-index the array. You can find the explication here : http://php.net/manual/en/language.types.array.php#language.types.array.useful-funcs
Use array_values().
<?php
$value = 22;
$numbers = array(4, 6, 2, 22, 11);
$arrlength = count($numbers);
for($y = 0; $y < $arrlength ; $y++) {
if ( $numbers[$y] == $value) {
unset($numbers[$y]);
}
}
$numbers = array_values($numbers);
$arrlength = count($numbers);
for($x = 0; $x < $arrlength; $x++) {
echo $numbers[$x];
echo "<br>";
}
?>
Check Online Demo : Click Here
OR
<?php
$value = 22;
$numbers = array(4, 6, 2, 22, 11);
$arrlength = count($numbers);
for($y = 0; $y < $arrlength ; $y++) {
if ( $numbers[$y] == $value) {
unset($numbers[$y]);
}
}
//$numbers = array_values($numbers);
//$arrlength = count($numbers);
foreach($numbers as $key=>$num) {
echo $num;
echo "<br>";
}
?>
you are trying to print element of not existing key
try this:
<?php
$value = 22;
$numbers = array(4, 6, 2, 22, 11);
$arrlength = count($numbers);
for($y = 0; $y < $arrlength ; $y++) {
if ( $numbers[$y] == $value) {
unset($numbers[$y]);
}
}
foreach($numbers as $k => $number)
echo "key: ". $k . " value: ". $number . "<br />";
I wanted to have a way to get all combinations for all given numbers with given array length.
In my project the array size usually is 7. So I write a test code like this to see if I can get all needed combinations. The important part is every result array must be unique and maximum array size must be 7.
<?php
$numbers = [1, 2, 3, 4, 5, 6, 7];
$arraysize = 7;
$subset = [];
$count = count($numbers);
for ($i = 0; $i < $count; $i++) {
$subset[] = $numbers[$i];
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
$subset[] = $numbers[$i] . $numbers[$j];
}
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
for ($k=$j; $k < $count; $k++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k];
}
}
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
for ($k=$j; $k < $count; $k++) {
for ($l=$k; $l < $count; $l++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k] . $numbers[$l];
}
}
}
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
for ($k=$j; $k < $count; $k++) {
for ($l=$k; $l < $count; $l++) {
for ($m=$l; $m < $count; $m++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k] . $numbers[$l] . $numbers[$m];
}
}
}
}
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
for ($k=$j; $k < $count; $k++) {
for ($l=$k; $l < $count; $l++) {
for ($m=$l; $m < $count; $m++) {
for ($n=$m; $n < $count; $n++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k] . $numbers[$l] . $numbers[$m] . $numbers[$n];
}
}
}
}
}
}
for ($i=0; $i < $count; $i++) {
for ($j=$i; $j < $count; $j++) {
for ($k=$j; $k < $count; $k++) {
for ($l=$k; $l < $count; $l++) {
for ($m=$l; $m < $count; $m++) {
for ($n=$m; $n < $count; $n++) {
for ($o=$n; $o < $count; $o++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k] . $numbers[$l] . $numbers[$m] . $numbers[$n] . $numbers[$o];
}
}
}
}
}
}
}
echo "<pre>";
print_r($subset);
echo "</pre>";
?>
When I run this code I get the combinations like I wanted (I make the combinations as string to see the results clearly but normally every result item in $subset array must be array)
With this code I can get all unique combinations.
But as you can see this code is ugly. I tried to make this a recursive function but I failed. Could anyone point me to right direction to get the exact same results like this? (every item in $subset array normally must be an array that contains digits)
You can simplify this logic (and make the code less ugly) without needing to go recursive by using:
for ($i = 0; $i < $count; $i++) {
$subset[] = $numbers[$i];
for ($j=$i; $j < $count; $j++) {
$subset[] = $numbers[$i] . $numbers[$j];
for ($k=$j; $k < $count; $k++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k];
for ($l=$k; $l < $count; $l++) {
$subset[] = $numbers[$i] . $numbers[$j] . $numbers[$k] . $numbers[$l];
}
}
}
}
the following will work in all cases even if you have duplicate numbers in your array
$array = array(1,2,3,4,5,6,7,8,9,10,11,12,13,14);
sort($array); //in case it 's not sorted
$array = array_slice($array,-7);
$num = count($array );
$total = pow(2, $num);
$result= array();
$element='';
for ($i = 0; $i < $total; $i++)
{
for ($j = 0; $j < $num; $j++)
{
if (pow(2, $j) & $i)
{
$element=$element.$array [$j];
}
}
$result[]=$element;
$element='';
}
print_r($result);
This implementation returns all the combinations of all items (77 = 823542 combinations of 7 items):
function combine_all(array $numbers) {
$count = count($numbers);
$result = array_map('strval', $numbers);
for($i = 1; $i < $count; ++$i) {
$combinations = array_slice($result, pow($count, $i-1));
foreach($numbers as $number) {
foreach($combinations as $combination) {
$result[] = $number . ',' . $combination;
}
}
}
return $result;
}
When using print_r to output the data, it can perform very slowly:
$array = array_fill(0, pow(7,7), '');
$t = microtime(true);
echo '<pre>';
print_r($array);
echo '</pre>';
echo microtime(true) - $t;
// 0.75329303741455
$t = microtime(true);
echo '<pre>';
print_r( combine_all(array(1,2,3,4,5,6,7)) );
echo '</pre>';
echo microtime(true) - $t;
// 1.7037351131439
$t = microtime(true);
combine_all(array(1,2,3,4,5,6,7));
echo microtime(true) - $t;
//0.75869607925415
To restrict the items number, use the array_slice function:
combine_all(array_slice($numbers, 0, 7));
If you really want a recursive function, you could do something like this:
function combine_all(array $numbers, $cnt=null, $baseCombination=null) {
if( $baseCombination === null ) {
$cnt = count($numbers);
}
if( $cnt > 0 ) {
$result = array();
foreach($numbers as $number) {
$combination = $number . ',' . $baseCombination;
$result[] = $combination;
$result = array_merge($result, combine_all($numbers, $cnt-1, $combination));
}
return $result;
}
return array();
}
But it takes too much memory.
I finally found out a way to add recursive function to create unique combinations from given numbers:
$numbers = [1, 2, 3, 4, 5, 6, 7];
function subsetSumRecursive($numbers, $arraySize, $level = 1, $i = 0, $addThis = [])
{
// If this is the last layer, use a different method to pass the number.
if ($level == $arraySize) {
$result = [];
for (; $i < count($numbers); $i++) {
$result[] = array_merge($addThis, array($numbers[$i]));
}
return $result;
}
$result = [];
$nextLevel = $level + 1;
for (; $i < count($numbers); $i++) {
// Add the data given from upper level to current iterated number and pass
// the new data to a deeper level.
$newAdd = array_merge($addThis, array($numbers[$i]));
$temp = subsetSumRecursive($numbers, $arraySize, $nextLevel, $i, $newAdd);
$result = array_merge($result, $temp);
}
return $result;
}
echo "<pre>";
print_r(subsetSumRecursive($numbers, 7));
echo "</pre>";
I am trying to create function that allows me to get all combinations of an array to later generate a list.
But my problem is that currently my function treat "ab" as different from "ba". I dont know how to explain it in words but I guess the picture below exemplify what I try to achieve.
function everyCombination($array) {
$arrayCount = count($array);
$maxCombinations = pow($arrayCount, $arrayCount);
$returnArray = array();
$conversionArray = array();
foreach ($array as $key => $value) {
$conversionArray[base_convert($key, 10, $arrayCount)] = $value;
}
for ($i = 0; $i < $maxCombinations; $i++) {
$combination = base_convert($i, 10, $arrayCount);
$combination = str_pad($combination, $arrayCount, "0", STR_PAD_LEFT);
$returnArray[] = strtr($combination, $conversionArray);
}
return $returnArray;
}
$a = everyCombination(array('a', 'b', 'c','d'));
print_r($a);
The desired ouput would be
a
ab
abc
abcd
b
bc
bcd
c
cd
d
What you need to do is iterate through the array recursively, for each recursion you should only iterate through all the greater elements. Like so:
function everyCombination($arr) {
$combos = array();
$len = count($arr);
for( $i=0; $i<$len; $i++) {
for( $j=$i+1; $j<=$len; $j++) {
$combos[] = implode("",array_slice($arr,$i,$j-$i));
}
}
return $combos;
}
Example call:
everyCombination(['a','b','c','d']);
Returns:
['a','ab','abc','abcd','b','bc','bcd','c','cd','d']
It seems that you're after consecutive results, so a double loop would be a better choice here; recursion requires more control.
function combos($array)
{
if (!$array) {
return [];
}
$n = count($array);
$r = [];
for ($i = 0; $i < $n; ++$i) {
$prefix = '';
for ($j = $i; $j < $n; ++$j) {
$r[] = $prefix . $array[$j];
$prefix .= $array[$j];
}
}
return $r;
}
print_r(combos([1, 2, 3, 4]));