I'm trying to get all the characters in that message at positions that are present in the Fibonacci sequence (a sequence formed by the the Fibonacci number sorted in ascending order). Please ignore whitespace characters and use the extended Fibonacci.
Return the obtained characters capitalized and connected by the '-' character.
Example
For message = "The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown",
the output should be
FibonacciSecret(message) = "T-H-H-E-D-V-C-E-M-T".
The first Fibonacci is 0 then the first letter is T
The second Fibonacci is 1 then the second letter is H
The third Fibonacci is 1 then the third letter is H ... and so on.
Thus, the answer should be "T-H-H-E-D-V-C-E-M-T".
Tried Code
<?php
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
$str_split = str_split($message);
$x = 0;
$y = 1;
for($i=0;$i<=10;$i++)
{
$z = $x + $y;
$farray[] = $z;
$x=$y;
$y=$z;
}
foreach($farray as $key=>$fvalue){
echo $str_split[$fvalue]."-";
}
?>
Output
h-T-
E_NOTICE : type 8 -- Undefined offset: -1 -- at line 18
-
E_NOTICE : type 8 -- Undefined offset: -1 -- at line 18
-T-h-h-T-
E_NOTICE : type 8 -- Undefined offset: -1 -- at line 18
-
E_NOTICE : type 8 -- Undefined offset: -1 -- at line 18
-T-
Expected Output
the answer should be "T-H-H-E-D-V-C-E-M-T".
Can anyone tell me. Where im going wrong in this one ?
Your Fibonacci series generation code was not correct, Try this:
Update:
This code will stop once it sum goes out of the range of message length.
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
// remove all the spaces from message
$message = str_replace(' ', '', $message);
$str_split = str_split($message);
$x = 0;
$y = 1;
$next = 0;
//stopping the loop if the character index goes out of range
for($i=1;$next<=count($str_split);$i++)
{
if($i == 1) //for first element use 0 as the sum
{
$farray[] = $x;
continue;
}
if($i == 2) //for second element use 1 as the sum
{
$farray[] = $y;
continue;
}
$next = $x + $y;
$x=$y;
$y=$next;
$farray[] = $next;
}
foreach($farray as $key=>$fvalue){
echo $str_split[$fvalue]."--";
}
Original Answer:-
It Works:-
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
// remove all the spaces from message
$message = str_replace(' ', '', $message);
$str_split = str_split($message);
$x = 0;
$y = 1;
$next = 0;
for($i=1;$i<=10;$i++)
{
if($i == 1) //for first element use 0 as the sum
{
$farray[] = $x;
continue;
}
if($i == 2) //for second element use 1 as the sum
{
$farray[] = $y;
continue;
}
$next = $x + $y;
$x=$y;
$y=$next;
$farray[] = $next;
}
foreach($farray as $key=>$fvalue){
echo $str_split[$fvalue]."--";
}
I think your Fibonacci logic is off. I munged up an example I found here: https://www.easycalculation.com/code-php-program-fibonacci-series.html
Sequence: 0, 1, 1, 2, 3, 5, 8, 13, 21, 34;
<?php
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
$str_split = str_split(str_replace(' ', '', $message));
$n_value = 10;
$first_value = 0;
$second_value = 1;
$next_value = 0;
$c_value = 0;
$letters = [];
for ( $c_value = 0 ; $c_value < $n_value ; $c_value++ )
{
if ( $c_value <= 1 ) {
$next_value = $c_value;
} else {
$next_value = $first_value + $second_value;
$first_value = $second_value;
$second_value = $next_value;
}
$letters[] = $str_split[$next_value];
}
echo implode($letters, "-");
Output:
T-h-h-e-D-V-c-e-m-t
Run it here: http://sandbox.onlinephpfunctions.com/code/45c72df556c19e239e09ba0e334ace1e40ce809c
Here's an interesting reference thread for PHP fibonacci: PHP Fibonacci Sequence
Edit: this code will return an undefined index because it doesn't stop when it exceeds strlen
Made a similar edit as @mkaatman
Here's my 3v4l: https://3v4l.org/5KIZD
<?php
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
$message = str_replace(' ', '', $message);
$str_split = str_split($message);
$x = 0;
$y = 1;
$farray[0] = 0;
$farray[1] = 1;
for($i=2;$i<=10;$i++)
{
$z = $x + $y;
$farray[] = $z;
$x=$y;
$y=$z;
}
foreach($farray as $key=>$fvalue){
//echo $key . " => " . $fvalue . "
";
echo $str_split[$fvalue]."-";
}
?>
Your code was almost correct.
You would delete spaces and add two start element of array.
$message = str_replace( ' ', '', 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown' );
$str_split = str_split( $message );
$x = 0;
$y = 1;
$farray[] = $x;
$farray[] = $y;
for ( $i = 2; $i <= 10; $i ++ ) {
$z = $x + $y;
$farray[] = $z;
$x = $y;
$y = $z;
}
foreach ( $farray as $key => $fvalue ) {
echo $str_split[ $fvalue ] . "-";
}
The shortest possible way would be just using the preg_replace and echo string position;
<?php
$message = 'The Da Vinci Code is a 2003 mystery-detective novel by Dan Brown';
$message = preg_replace('/\s+/', '', $message);
$strlenggth = strlen($message);
echo $message[$x];
$x = 0;
$y = 1;
for($i=0;$x<=$strlenggth;$i++)
{
$z = $x + $y;
$farray[] = $z;
$x=$y;
$y=$z;
echo "-".$message[$x];
}
?>
Alternatively, you can use recursion to avoid using too many for loops:
$message = str_replace(" ", "", $message);
for($i = 0; $i < 10; $i++) {
echo substr($message, getNthValue($i), 1);
if($i != 9) {
echo "-";
}
}
function getNthValue($n) {
if($n <= 1) {
return $n;
}
if($n > 1) {
return getNthValue($n-1) + getNthValue($n-2);
}
}
Recursive version and wrapped in a function, string length should be irrilevant:
function fiboSecret($msg, $num = 0, $fib = [], $secret = []){
if(count($fib) > 0) {
if($num == 1){
if(strlen($msg) > 1){
$secret[] = strtoupper($msg[1]);
return fiboSecret($msg, ++$num, array(0, 1), $secret);
}else{
return $secret;
}
}
$lastFibo = $fib[count($fib) - 1];
if(array_key_exists($lastFibo, str_split($msg))){
$secret[] = strtoupper($msg[$lastFibo]);
$fib[] = $fib[$num-1] + $fib[$num-2];
return fiboSecret($msg, ++$num, $fib, $secret);
}else{
return $secret;
}
}else if(strlen($msg) > 0){
$msg = preg_replace('/\s+/', '', $msg);
$secret[] = strtoupper($msg[0]);
return fiboSecret($msg, ++$num, array(0), $secret);
}else{
return [];
}
if(array_key_exists($lastFibo, str_split($msg))){
$secret[] = strtoupper($msg[$lastFibo]);
$num++;
}
}