Finding out all the expressions within brackets

Finding out all the expressions within brackets : I was actually asked to find out the smallest bracket expression within an expression, I have omitted the function to check for the smallest string and omitting spaces within the expression.

This was actually an interview question at a startup in Seawoods, Navi Mumbai.

Given an expression like ((a + b * d) * (x / 2)) * (1 + (y + (x - 2) / 10)) the smallest expression within brackets is x / 2 and x - 2. If we can find all the expressions within the brackets, then finding the smallest ones is as simple enough by finding the length after removing the spaces.

<?php
$s = "((a + b * d) * (x / 2)) * (1 + (y + (x - 2) / 10))";
$b = [];
$j = 0;
$stack = [];

for ($i = 0; $i < strlen($s); $i++)
{   
    if ($s[$i] == '(')
    {       
        $b[++$j] = '';
    }
    elseif ($s[$i] == ')')
    {       
        $stack[] = ($b[$j--] .= ')');   
    }
    for ($k = 1; $k <= $j; $k++)
    {
        $b[$k] .= $s[$i];
    }
}
echo $s.PHP_EOL;
print_r($stack);
echo PHP_EOL;
?>

php brackets.php 
((a + b * d) * (x / 2)) * (1 + (y + (x - 2) / 10))
Array
(
    [0] => (a + b * d)
    [1] => (x / 2)
    [2] => ((a + b * d) * (x / 2))
    [3] => (x - 2)
    [4] => (y + (x - 2) / 10)
    [5] => (1 + (y + (x - 2) / 10))
)

Finding out all the expressions within brackets

Comments

More from this blog

Email validity checker using Google's JSON API for DNS over HTTPS (DoH) in Google Sheets

Getting picoclaw to work on Windows

The core use-case of TypeScript

Hashnode's GraphQL API for RSS feeds

make makemigrations work again

Command Palette

Comments

More from this blog