PalindromesMay 3, 2007A palindrome is a number or a text that reads the same forwards and backwards. An object that has an axis of symmetry. Problem #36 on project Eueler is to find the sum of all numbers less than one million, which are palindromic in base 10 and base 2. it's one of the easier ones on that site. Here is the solution in PHP.
$sum=0;
for($i=1 ; $i < 1000001 ; $i++)
{
$prod = $i;
$rev = strrev($i);
if($prod == $rev)
{
$binp = sprintf("%b",$prod);
$rev = strrev($binp);
//echo "$binp - > $rev \n";
if($rev == $binp)
{
printf("Match for %d - %b\n",$prod,$prod);
$sum = $sum + $prod;
}
}
}
echo "\nTHE SUM = $sum \n";
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