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#!/usr/bin/env perl
use v5.20;
use utf8;
use strict;
use warnings;
use autodie;
use feature qw(say signatures);
no warnings 'experimental::signatures';
#
# You are given a positive number $N.
#
# Write a script to count the total numbrer of set bits of the binary
# representations of all numbers from 1 to $N and return
# $total_count_set_bit % 1000000007.
my ($N) = @ARGV;
say count_set_bits($N) % 1000000007;
sub count_set_bits($n) {
my $count = 0;
my $i = 0;
while ( (1 << $i) <= $n ) {
my $set = 0;
my $change_after = 1 << $i;
for ( 0 .. $n ) {
$count += $set;
if ( $change_after == 1 ) {
$set = !$set;
$change_after = 1 << $i;
}
else {
$change_after--;
}
}
$i++;
}
return $count;
}
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