PHP Exercises: Restore the original string by entering the compressed string with this rule

Last update on May 30 2022 11:45:41 (UTC/GMT +8 hours)

PHP: Exercise-72 with Solution

When character are consecutive in a string , it is possible to shorten the character string by replacing the character with a certain rule. For example, in the case of the character string YYYYY, if it is expressed as # 5 Y, it is compressed by one character.
Write a PHP program to restore the original string by entering the compressed string with this rule. However, the # character does not appear in the restored character string.
Note: The original sentences are uppercase letters, lowercase letters, numbers, symbols, less than 100 letters, and consecutive letters are not more than 9 letters.

Input: Multiple character strings are given. One string is given per line

Sample Solution: -

PHP Code:

<?php
$str  = "@88 + 1 = [email protected]";
    $index = 0;
    $result = array();
    while($index < strlen($str)) {
        $t = $str[$index++];
        if ($t == "@") {
            $len = $str[$index++];
            $char = $str[$index++];
            $run = "";
            for ($i = 0; $i < $len; $i++) {
                $run .= $char;
            }
            $result[] = $run;
        } else {
            $result[] = $t;
        }
    }
    echo implode("", $result);
?>

Sample Input:
@88 + 1 = [email protected]

Sample Output:

88888888 + 1 = 100000000

Flowchart:

PHP Code Editor:

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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