<?php
$namesList = implode('', file(__DIR__ . '/data/p022_names.txt'));
$names = explode(',', $namesList);
foreach ($names as $k => $v) {
$names[$k] = trim($v, '"');
}
sort($names);
$n = count($names);
$totalScore = 0;
for ($i = 0; $i < $n; ++$i) {
$thisNameScore = nameScore($names[$i]) * ($i + 1);
$totalScore += $thisNameScore;
}
echo $totalScore . "\n";
function nameScore($name)
{
$score = 0;
$n = strlen($name);
for ($i = 0; $i < $n; ++$i) {
$score += ord(substr($name, $i, 1)) - ord('A') + 1;
}
return $score;
}
?>
*
* For example, the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110; therefore d(220) = 284.
* The proper divisors of 284 are 1, 2, 4, 71 and 142; so d(284) = 220.
*
* Evaluate the sum of all the amicable numbers under 10000.
*
* Solution: For each number 2 to 10000, check if it is amicable with the sum of its factors. Too brute force.
* Must refactor.
*/
include "helper.php";
function nameScore($name, $position)
{
global $letters;
$nameChars = str_split(strtolower($name));
$nameScore = 0;
foreach ($nameChars as $char) {
$nameScore += $letters[$char];
}
return $nameScore * $position;
}
$letters = array('0' => 0, 'a' => 1, 'b' => 2, 'c' => 3, 'd' => 4, 'e' => 5, 'f' => 6, 'g' => 7, 'h' => 8, 'i' => 9, 'j' => 10, 'k' => 11, 'l' => 12, 'm' => 13, 'n' => 14, 'o' => 15, 'p' => 16, 'q' => 17, 'r' => 18, 's' => 19, 't' => 20, 'u' => 21, 'v' => 22, 'w' => 23, 'x' => 24, 'y' => 25, 'z' => 26);
$total = 0;
$x = 1;
$namesFile = fopen('./assets/022-names.txt', 'r');
$names = explode(",", fread($namesFile, 99000));
sort($names);
foreach ($names as $name) {
$total += nameScore(str_replace('"', '', $name), $x);
$x++;
}
result(871198282, $total);
