#!/usr/bin/perl -w use strict; use Memoize; # Fibonacci sequence # 2021-04-25, LTu sub fibo { $_[0] < 2 ? $_[0] : fibo($_[0] - 1) + fibo($_[0] - 2) } memoize('fibo'); printf "%s\n", fibo($ARGV[0]) ### Intel Core m3 1.2 HHz, without memoize # # $ time ./fibo.pl 40 # # 102334155 # # real 1m10.381s # user 1m6.836s # sys 0m0.272s # # ### with memoize # # $ time ./fibo.pl 40 # # 102334155 # # real 0m0.067s # user 0m0.020s # sys 0m0.011s