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

Last update on May 30 2022 11:44:11 (UTC/GMT +8 hours)

PHP Challenges - 1: Exercise-7 with Solution

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

Input : (array(2, 7, 7, 1, 8, 2, 7, 8, 7), 16))

Sample Solution :

PHP Code :

<?php
function three_Sum($arr, $target)
{
$count = count($arr) - 2;
$result=[];
for ($x = 0; $x < $count; $x++) {
    if ($arr[$x] + $arr[$x+1] + $arr[$x+2] == $target) {
        array_push($result, "{$arr[$x]} + {$arr[$x+1]} + {$arr[$x+2]} = $target");
    }
}
return $result;
}
$my_array = array(2, 7, 7, 1, 8, 2, 7, 8, 7);
print_r(three_Sum($my_array, 16));
print_r(three_Sum($my_array, 11));
print_r(three_Sum($my_array, 12));
?>

Sample Output:

Array                                                       
(                                                           
    [0] => 2 + 7 + 7 = 16                                   
    [1] => 7 + 1 + 8 = 16                                   
)                                                           
Array                                                       
(                                                           
    [0] => 1 + 8 + 2 = 11                                   
)                                                           
Array                                                       
(                                                           
)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to find three numbers from an array such that the sum of three consecutive numbers equal to zero.
Next: Write a PHP program to compute and return the square root of 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