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Challenge 079

Table of Contents

Task 1 - Count Set Bits

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.

Perl

We loop from 1 ... $input, convert each $num to binary & count the set bits & add them to $set_bits.

my $input = shift @ARGV;

my $set_bits;
foreach my $num (1 ... $input) {
    my $binary = sprintf "%b", $num;
    my $count = $binary =~ tr/1//;
    $set_bits += $count;
}
print $set_bits % 1000000007, "\n";

Andinus / / Modified: 2020-10-20 Tue 18:22 Emacs 27.1 (Org mode 9.4)