PHP Exercises: Check a given array of integers and return true if the array contains three increasing adjacent numbers

Last update on May 30 2022 11:41:06 (UTC/GMT +8 hours)

PHP Basic Algorithm: Exercise-123 with Solution

Write a PHP program to check a given array of integers and return true if the array contains three increasing adjacent numbers.

Sample Solution:

PHP Code :

<?php
function test($numbers)
    { 
       for ($i = 0; $i <= sizeof($numbers) - 3; $i++)
          {
             if ($numbers[$i] == $numbers[$i + 1] - 1
                 && $numbers[$i] == $numbers[$i + 2] - 2)
               {
                  return true;
                }
          }
          return false;
      }   

var_dump(test([1, 2, 3, 5, 3, 7]));
var_dump(test([3, 7, 5, 5, 3, 7]));
var_dump(test([3, 7, 5, 5, 6, 7, 5]));

Sample Output:

bool(true)
bool(false)
bool(true)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to check a given array of integers and return true if the specified number of same elements appears at the start and end of the given array.
Next: Write a PHP program to shift an element in left direction and return a new array.

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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