php algorithm

algorithm_100_doors.php

<?php

/**
* 100 doors problem set
*/

// toggle state for doors
$toggleState = array('open' => 'closed', 'closed' => 'open');
// init all doors as closed
$doors = array_fill(1, 100, 'closed');

for($pass=1; $pass<=100; ++$pass){
	for($nr =1; $nr <=100; ++$nr){
		if($nr % $pass == 0){
			$doors[$nr] = $toggleState[$doors[$nr]];
		}
	}
}

for($nr=1; $nr<=100; ++$nr){
	//printf("Door %d is %s\n", $nr, $doors[$nr]);

}

// optimized version 
for($i=1; $i<=100; $i++){
	$root = sqrt($i);
	$state = ($root == ceil($root)) ? 'open' : 'closed';
	echo "Door {$i}: {$state}\n";
}

algorithm_24_game.php

<?php
 
while (true) {
    $numbers = make_numbers();
 
    for ($iteration_num = 1; ; $iteration_num++) {
        echo "Expresion $iteration_num: ";
 
        $entry = rtrim(fgets(STDIN));
 
        if ($entry === '!') break;
        if ($entry === 'q') exit;
 
        $result = play($numbers, $entry);
 
        if ($result === null) {
            echo "That's not valid\n";
            continue;
        }
        elseif ($result != 24) {
            echo "Sorry, that's $result\n";
            continue;
        }
        else {
            echo "That's right! 24!!\n";
            exit;
        }
    }
}
 
function make_numbers() {
    $numbers = array();
 
    echo "Your four digits: ";
 
    for ($i = 0; $i < 4; $i++) {
        $number = rand(1, 9);
        // The check is needed to avoid E_NOTICE from PHP
        if (!isset($numbers[$number])) {
            $numbers[$number] = 0;
        }
        $numbers[$number]++;
        print "$number ";
    }
 
    print "\n";
 
    return $numbers;
}
 
function play($numbers, $expression) {
    $operator = true;
    for ($i = 0, $length = strlen($expression); $i < $length; $i++) {
        $character = $expression[$i];
 
        if (in_array($character, array('(', ')', ' ', "\t"))) continue;
 
        $operator = !$operator;
 
        if (!$operator) {
            if (!empty($numbers[$character])) {
                $numbers[$character]--;
                continue;
            }
            return;
        }
        elseif (!in_array($character, array('+', '-', '*', '/'))) {
            return;
        }
    }
 
    foreach ($numbers as $remaining) {
        if ($remaining > 0) {
            return;
        }
    }
 
    return eval("return $expression;");
}

algorithm_99_bootles_of_beer.php

<?php

/**
* 99 bootles of beer problem set
*/

$plural = 's';
foreach(range(1, 99) as $i){
	echo "$i bootle$plural of beer on the wall \n";
	echo "$i bottle$plural of beer!\n";
	echo "Take one down, pass it around!\n";
	if ($i - 1 == 1)
        $plural = '';
 
    if ($i > 1)
        echo ($i - 1) . " bottle$plural of beer on the wall!\n\n";
    else
        echo "No more bottles of beer on the wall!\n";
}

algorithm_a+b.php

<?php

fscanf(STDIN, "%d %d\n", $a, $b); //Reads 2 numbers from STDIN
echo ($a + $b) . "\n";

algorithm_abc_problem.php

<?php
/**
* abc problem set 
*
*/
$words = array("A", "BARK", "BOOK", "TREAT", "COMMON", "SQUAD", "Confuse");
 
function canMakeWord($word) {
    $word = strtoupper($word);
    $blocks = array(
            "BO", "XK", "DQ", "CP", "NA",
            "GT", "RE", "TG", "QD", "FS",
            "JW", "HU", "VI", "AN", "OB",
            "ER", "FS", "LY", "PC", "ZM",
    );
 
    foreach (str_split($word) as $char) {
        foreach ($blocks as $k => $block) {
            if (strpos($block, $char) !== FALSE) {
                unset($blocks[$k]);
                continue(2);
            }
        }
        return false;
    }
    return true;
}
 
foreach ($words as $word) {
    echo $word.': ';
    echo canMakeWord($word) ? "True" : "False";
    echo "\r\n";
}

algorithm_anagram.php

<?php
/**
 * Anagram finder function
 * Check if word is an anagram for any word in provided dictionary
 */

function anagram_finder($anagram, $dictionary)
{
    // the array for successful words
    $match_words = array();

    // split anagram word by ASCII codes and how many times occured
    $anagram_letters = count_chars($anagram, 1);

    // for each word in dictinary...
    foreach($dictionary as $word){
        // split word by chars
        $letters = count_chars($word, 1);

        // for each char...
        foreach($letters as $key => $amount){
            // skip the word if any char not exist in anagram word or its number is bigger than in anagram word
            if(!array_key_exists($key, $anagram_letters) || $amount > $anagram_letters[$key]){
                continue 2;
            }
        }
        // if was not skipped - put word to successful words array
        $match_words[] = $word;
    }
    return $match_words;
}

$dictionary = array("bomb", "auto", "rome", "plane", "elephant");
$results = anagram_finder("pbaluromateobom", $dictionary);
print_r($results);

algorithm_Symmetric_difference.php

<?php
/**
 * Symmetric_difference between two arrays problem
 */

// input arrays
$array1 = array(1, 7, 8, 2, 4, 5);
$array2 = array(3, 5, 1, 7, 6, 9);
// output arrays
$result1 = array();
$result2 = array();
$total_result = array();
// remove any duplicates before running to be faster in comparing arrays for processor
$array1 = array_unique($array1);
$array2 = array_unique($array2);
// get differences from array1 against array2
$result1 = array_diff($array1, $array2);
// get differences from array2 against array1
$result2 = array_diff($array2, $array1);
// simply merge together both result set into one array
$total_result = array_merge($result1,$result2);

var_dump($total_result);

Php Algorithm

Hello this will be place for solve and test some algorithms and tricks i can handle them using php programming language 

words-combinations

<?php
/**
 * find possible paragraphs based on those words
 * given array
 * result paragraph
 */

$words = array('php','love','technology','hackers','travel','thinking');
// first of all i will use simple computing math rule 2^n can give you possible combinations such as binary 2^5=32 etc ..
// use power function
$total = count($words);
// this will give us possible combination 2^6=64
$possible = pow(2,$total);
/***
 *  repersent them in binary like this
* 0  0  0
 * 0  0  1
 * 0  1  0
 *  0 1  1
 * etc ...
 * */
// loop throw each column
for($i=0; $i<$possible; $i++){
   // foreach combination check if each bit is set
    for($j=0; $j < $possible; $j++){
        if(pow(2,$j) & $i) echo $words[$j].' ';
    }
    echo "\n";
}