Skip to main content

Interview question #2

This is related to PHP's array.

An array has number of elements. All elements are integers and unique, which means there is no repetitive integers.
(e.g.) $foo = array(7, 5, 9, 13, 2, 8);

You have to sort the array, provided:
  1. You should scan the elements only once.
  2. You're not allowed to compare the elements when sorting. (i.e., you're not supposed to use any comparison operators)
  3. Sorted resultant array may not be the source array.
How will you do that?

Comments

Anonymous said…
$foo = array(7, 5, 9, 13, 2, 8);

reset($foo);

$bar = array();
$barcount = 0;
while ($foo <> array()) {
$bartemp = min($foo);
$bar[$barcount] = $bartemp;
unset($foo[array_search($bartemp, $foo)]);
$barcount++;
}
print_r($foo); //empty
echo "\n";
print_r($bar); //sorted!
?>


Result:
$foo is Array
(
)

$bar is Array
(
[0] => 2
[1] => 5
[2] => 7
[3] => 8
[4] => 9
[5] => 13
)
Anonymous said…
$bar = $foo;
sort($bar);
reset($bar);
print_r($bar);
For comment#1:You are using min() which is again a comparison function. The answer is not that complex at all.

For comment#2:Are you kidding;)
Anonymous said…
http://us4.php.net/manual/en/language.operators.comparison.php
For comment#4:I meant that you're not allowed to compare the elements in anyway (using operators or functions). Probably I should have worded it better.
Anonymous said…
##Deadeasy##

Popular posts from this blog

Humble Award - Dr. A.N. Sreevatsan

Dr. A.N. Sreevatsan , ENT specialist located in Adyar, Chennai is one of the gems available in medicines. No assistants in his consulting room and he'd take at least 15mins for every patients. So far I have referred many and all are happy with his approach. Every wannabe doctor should visit him personally to understand his approach. I wish him to be more famous than now. Update (2010-11-21) : Added link to Google Map Keywords : Sreevatsan, Srivatsan, ENT, Adyar, Chennai, Hospital, Doctor

BehaviorS.js - An alternative to Behaviour.js, event:Selectors and Low Pro libs for unobtrusive JavaScript programming

BehaviorS.js yet another unobtrusive JavaScript library similar to Behaviour.js and event:Selectors but in implementation uses hash based lookup without extending elements; so presumably it should be faster than the rest. The original script and idea was by JLof ; I extended it for DOMContentLoaded support, optimized a bit to avoid scanning of more depths, and added new rules support. I wanted to document the plug a long time and just got time to do it. For the time being BehaviorS.js is available here Update (2006-09-11) : Coralized the link to BehaviorS.js so as to save the load on free brinkster.com webpage Update (2006-09-27) : If the coralized link to BehaviorS.js doesn't work, use http://www21.brinkster.com/guideme/BehaviorS/ Update (2025-06-07) : Now available in https://github.com/rrjanbiah/behaviorsjs

Anna Hazare hype, irresponsibile media?

In recent times, barkhagate scam clearly shows that the Indian media is much corrupt than the politicians. They give unnecessary hype to certain things to get TRP . Ever since Anna has gone compared himself with Gandhi and Shivaji , it was clear that he's trying to draw politicians attention. It was a clean tactic than what Medha Patkar or any maoists couldn't get such hype. The TwitGens [sic] can't really understand how a Lokpal (ombudsman) system can even be corrupt; remember that the author of Savaukku did quit from DVAC (Directorate of Vigilance and Anti-Corruption). Economic Times article on this issue shares my views; I don't understand why they couldn't get such views published in Times of India. I think, we can't expect anything good from the media that's vehemently pushing AIADMK. Will Lok Pal be a Super Bureaucrat? Anna Hazare: Was Lok Pal protest compatible with constitutional democracy?