/*
calculates two strings to a new string ... calc("1234", "1234") -> "2468"
*/
function calc($a, $b){
$result = "";//final result
$len_1 = strlen($a);
$len_2 = strlen($b);
if($len_1 > $len_2){
$up = $len_1;
}else{
$up = $len_2;
}
$a = strrev ( $a );
$b = strrev ( $b );
$arr1 = str_split($a);
$arr2 = str_split($b);
for($i = 0;$i < ($up+1);$i++){
$numb = $jj + $arr1[$i] + $arr2[$i];
if($numb >= 10){
$jj = 1;
$numb = ($numb % 10);
}else{
$jj = 0;
}
$result = $numb."".$result;
}
return ltrim($result, "0");
}
$fibo_1 = "1";
$fibo_2 = "1";
for($i = 1;$i <= 201;$i++){
$new = calc($fibo_1, $fibo_2);
echo "".$new."";
if($i % 2 == 0){
$fibo_1 = $new;
}else{
$fibo_2 = $new;
}
}