function Fib($n)
{
if ($n == 0 || $n == 1) {
return 1;
} else {
return Fib($n - 2) + Fib($n - 1);
}
}
function Fib($n)
{
global $FV;
if (!is_int($n) || $n < 0) {
return 0;
}
if (!isset($FV[$n])) {
$FV[$n] = Fib($n - 2) + Fib($n - 1);
}
return $FV[$n];
}
<?php
/**
* Write an integer function Fib(N) that returns the value of N-th term of the sequence of the
* Fibonacci numbers. The Fibonacci numbers FK are defined as follows:
* F1 = 1, F2 = 1, FK = FK−2 + FK−1, K = 3, 4, … .
* sing this function, find five Fibonacci numbers with given order numbers N1, N2, …, N5.
*/
function Fib($N)
{
$x = 0;
$y = 1;
$z = 0;
while ($z < $N) {
$z = $x + $y;
echo $z . "<br />";
$x = $y;
$y = $z;
}
}
Fib(50);