PHP Challenges: Find three numbers from an array such that the sum of three consecutive numbers equal to zero

Last update on May 30 2022 11:49:13 (UTC/GMT +8 hours)

PHP Challenges - 1: Exercise-6 with Solution

Write a PHP program to find three numbers from an array such that the sum of three consecutive numbers equal to zero.

Input : (-1,0,1,2,-1,-4)

Explanation :

PHP: Find three numbers from an array such that the sum of three consecutive numbers equal to zero

Sample Solution :

PHP Code :

<?php
function three_Sum_zero($arr)
{
$count = count($arr) - 2;
$result=[];
for ($x = 0; $x < $count; $x++) 
{
    if ($arr[$x] + $arr[$x+1] + $arr[$x+2] == 0)
    {
        array_push($result, "{$arr[$x]} + {$arr[$x+1]} + {$arr[$x+2]} = 0");
    }
}
return $result;
}
$nums1= array(-1,0,1,2,-1,-4);
$nums2 = array(-25,-10,-7,-3,2,4,8,10);

print_r(three_Sum_zero($nums1));
print_r(three_Sum_zero($nums2));
?>

Sample Output:

Array                                                       
(                                                           
    [0] => -1 + 0 + 1 = 0                                   
)                                                           
Array                                                       
(                                                           
)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to find a missing number(s) from an array.
Next: Write a PHP program to find three numbers from an array such that the sum of three consecutive numbers equal to a given number.

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PHP: Tips of the Day

How to Sort Multi-dimensional Array by Value?

Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

Example:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual

Ref : https://bit.ly/3i77vCC