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

Last update on May 28 2025 13:07:09 (UTC/GMT +8 hours)

123. Contains Three Increasing Adjacent Numbers

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
// Define a function named 'test' that takes an array of numbers as a parameter
function test($numbers)
{ 
    // Iterate through the elements of the array using a for loop
    for ($i = 0; $i <= sizeof($numbers) - 3; $i++)
    {
        // Check if the current element is equal to the next element minus 1
        // and if the current element is equal to the element after the next element minus 2
        if ($numbers[$i] == $numbers[$i + 1] - 1 && $numbers[$i] == $numbers[$i + 2] - 2)
        {
            // Return true if the condition is met
            return true;
        }
    }

    // Return false if the condition is not met for any set of three consecutive elements
    return false;
}   

// Use 'var_dump' to print the result of calling 'test' with different arrays
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:

For more Practice: Solve these Related Problems:

Write a PHP script to detect whether an array contains any three consecutive increasing numbers.
Write a PHP function to iterate over an array and return true if a subsequence of three elements is strictly increasing.
Write a PHP program to use a sliding window over an array and check if each trio is in ascending order.
Write a PHP script to implement logic that compares consecutive triplets in an array to determine if an increasing pattern exists.

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