Codility.com Tests 100/100 Solutions
Lesson 8 – Prime and composite numbers – Peaks demo task solution code written in php. Gives 100/100 score at the time of publishing.
The description of the problem is copyrighted, so please see the following link for it: https://codility.com/demo/take-sample-test/peaks
Solution in php:
function solution($A) {
$n = count($A);
if ($n <= 2) {
return 0;
}
$sum = array_fill(0,$n,0);
$last = -1;
$D = 0;
$sum[0] = 0;
for ($i = 1; $i + 1 < $n; ++$i) {
$sum[$i] = $sum[$i - 1];
if (($A[$i] > $A[$i - 1]) && ($A[$i] > $A[$i + 1])) {
$D = max($D, $i - $last);
$last = $i;
++$sum[$i];
}
}
if (($sum[$n - 1] = $sum[$n - 2]) == 0) {
return 0;
}
$D = max($D, $n - $last);
for ($i = ($D >> 1) + 1; $i < $D; ++$i) {
if ($n % $i == 0) {
$last = 0;
for ($j = $i; $j <= $n; $j += $i) {
if ($sum[$j - 1] <= $last) {
break;
}
$last = $sum[$j - 1];
}
if ($j > $n) {
return $n / $i;
}
}
}
for ($last = $D; $n % $last; ++$last){
;
}
return intval($n / $last);
}
Given “AS IS”, can be ported from other languages from solutions found on the internet, please use with care.
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