ビット構成を表示する

明解Ｃ言語入門編 > 7. 基本型 >

C



#include <stdio.h>
int count_bits(unsigned x)

{

    int count = 0;

    while (x)

    {

        if (x & 1u) count++;

        x >>= 1;

    }

    return count;

}
int int_bits(void)

{

    return count_bits(~0u);

}
void print_bits(unsigned x)

{

    int i;

    for (i = int_bits() - 1; i >= 0; i--)

        putchar(((x >> i) & 1u) ? '1' : '0');
    putchar('\n');

}
int main(int argc, char* argv[])

{

    unsigned x = 10000;

    print_bits(x);
    return 0;

}

実行結果



R:\>lesson055\project1.exe

00000000000000000010011100010000

Delphi



program Project1;
{$APPTYPE CONSOLE}
uses

    SysUtils;
var

    x:Longword;
function count_bits(x:Longword):Integer;

var

    count:Integer;

begin

    count := 0;

    while (x <> 0) do

    begin

        if x and 1 <> 0 then inc(count);

        x := x shr 1;

    end;

    result := count;

end;
function int_bits():Integer;

begin

    result := count_bits(Longword(not 0));

end;
procedure print_bits(x:Longword);

var

    i: Integer;

begin

    for i := int_bits() - 1 downto 0 do

    begin

        if x shr i and 1 <> 0 then

            write('1')

        else

            write('0');

    end;
    writeln('');

end;
begin

    x := 10000;

    print_bits(x);

end.

実行結果



S:\>lesson055\project1.exe

00000000000000000010011100010000

Perl

sub count_bits
{
    my ($x) = @_;
    $count = 0;
    while ($x)
    {
        $count++ if ($x & 1) ;
        $x >>= 1;
    }
    return $count;
}

sub int_bits
{
    return &count_bits(~0);
}

sub print_bits
{
    my ($x) = @_;
    for ($i = &int_bits - 1; $i >= 0; $i--)
    {
        print ((($x >> $i) & 1) ? '1' : '0');
    }

    print "\n";
}

$x = 10000;
&print_bits($x);

実行結果



L:\>perl lesson_07_055.pl

00000000000000000010011100010000

Ruby

def count_bits(x)
    count = 0
    while (x != 0)
        count += 1 if (x & 1 != 0) 
        x = (x >> 1) & ~(~0 << (x.size * 8))
    end
    return count
end

def int_bits
    return count_bits(~0)
end

def print_bits(x)
    (int_bits - 1).downto(0) do |i|
        print(((x >> i) & 1) != 0 ? '1' : '0')
    end

    puts ""
end

x = 10000
print_bits(x)

実行結果



L:\>ruby  l:\lesson_07_055.rb

000000000000000000010011100010000