Subscribed unsubscribe Subscribe Subscribe

Kentaro Kuribayashi's blog

Software Engineering, Management, Books, and Daily Journal.

How Many Days Required until All Your Blog are Belong to Hatena Blog?

Hatena Blog gives us 1 invitation right per day. How long will it be all the people on the earth start using Hatena Blog when they always invite everyday those who haven't started Hatena Blog?

#!/usr/bin/env perl
use strict;
use warnings;

sub all_your_blog_are_belong_to_us {
    my ($blog_count, $days, $limit) = @_;
    if ($blog_count >= $limit) {
        say $days;
    else {
        all_your_blog_are_belong_to_us($blog_count * 2, ++$days, $limit);

all_your_blog_are_belong_to_us(1, 1, 7_000_000_000);

Only 34 days!