Find repeating part of repeating decimal -- PHP
php
Solution
Gotta say this isn't as easy as i thought it'd be. but i got it working. I'm sure there is a more efficient way of doing this, hopefully someone else will improve upon this. Especially the part where it gets printed.
$number1 = $number / $divisor;
if(findRepeat( $number1 ) !== false)
{
$result = findRepeat($number1);
$leadingNum = strstr($number1, '.', true);
$nonRepeat = substr($number1, strpos($number1, '.') + 1 , $result['position']);
if($nonRepeat == '')
$nonRepeat = '.';
$repeat = substr($number1,strpos($number1,$nonRepeat) + strlen($nonRepeat), $result['patternSize']);
$nonRepeat = $nonRepeat == '.' ? '.' : '.'.$nonRepeat;
echo $leadingNum.$nonRepeat."<span style='text-decoration:overline'>".$repeat."</span>";
}
else
echo number_format( $number1 , 6);
now for the function
function findRepeat($number)
{
$maxLength = 6;
$decimal = substr($number, strpos($number,'.') + 1 );
if(strlen($decimal) >= $maxLength )
$decimal = substr($decimal,0, $maxLength);
else
$maxLength = strlen($decimal);
for($i =0; $i < $maxLength - 3; ++$i)
{
//check for single repeition
if( $decimal[$i] == $decimal[$i + 1] && $decimal[$i + 1] == $decimal[$i+2])
return array('position'=>$i,'patternSize'=>1);
//triple repetition
if(substr($decimal,$i,3) == substr($decimal, $i + 3, 3) )
return array('position'=>$i,'patternSize'=>3);
//double repetition
if(substr($decimal,$i,2) == substr($decimal, $i + 2, 2) )
return array('position'=>$i,'patternSize'=>2);
}
return false;
}
Problem
I'm randomly generating repeated decimals using this code... ``` do{ $divisor_array = array(3, 6, 9, 11, 22, 33); $divisor = $divisor_array[array_rand($divisor_array)]; $number = mt_rand(1, 100); $decimal_value = $number / $divisor; } while (strlen($decimal_value) < 5); echo $number / $divisor; ``` I want to then display that number with the repeating bar over the repeating part. Example: 5.83434343434343.... would be 5.8`<span style="text-decoration: overline;">34</span>` Any ideas on how to do this if the repeating decimals are being randomly generated?