This is not a good way to do fib, but it does illustrate my point:

use strict;

for my $i (0 .. 35) {
    print "i=$i ... fib(i)=", &fib($i), "\n";
}

sub fib {
    my $n = shift;

    return &fib($n-1) + &fib($n-2) if $n>1;
    return 1;
}
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versus

int fib(int n) {
    if( n > 1 )
        return fib(n-1) + fib(n-2);

    return 1;
}

int main() {
    int i;

    for(i=0; i<36; i++)
        printf("i=%d ... fib(i)=%d\n", i, fib(i));

    return 0;
}
[download]