Fibonacci sequence: Difference between revisions

=={{header|PL/0}}==

The program waits for ''n''. Then it displays ''n''^th Fibonacci number.

<syntaxhighlight lang="pascal">

var n, a, b, i, tmp;

begin

? n;

a := 0; b := 1;

i := 2;

while i <= n do

begin

tmp := b; b := a + b; a := tmp;

i := i + 1

end;

! b;

end.

</syntaxhighlight>

4 runs.

{{in}}

<pre>5</pre>

{{out}}

<pre> 5</pre>

{{in}}

<pre>9</pre>

{{out}}

<pre> 34</pre>

{{in}}

<pre>13</pre>

{{out}}

<pre> 233</pre>

{{in}}

<pre>20</pre>

{{out}}

<pre> 6765</pre>