文字列内の数字の出現回数を数える

明解Ｃ言語入門編 > 9. 文字列の基本 >

C



#include <stdio.h>


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

{

    int      cnt[10]  = {0};

    char     str[100] = "3.1415926535897932846";

    unsigned i        = 0;
    while (str[i])

    {

        if (('0' <= str[i]) && (str[i] <= '9'))

            cnt[str[i] - '0']++;

        i++;

    }
    for (i = 0; i < 10; i++)

    {

        printf("'%d' : %d\n", i, cnt[i]);

    }
    return 0;

}

実行結果



R:\>lesson074\Project1.exe

'0' : 0

'1' : 2

'2' : 2

'3' : 3

'4' : 2

'5' : 3

'6' : 2

'7' : 1

'8' : 2

'9' : 3

Delphi



program Project1;
{$APPTYPE CONSOLE}
uses

    SysUtils;
procedure main();

var

    i, j: Integer;

    str:  String;

    cnt:  array[0..9] of Integer;

begin

    str := '3.1415926535897932846';
    for i := 0 to 9 do

        cnt[i] := 0;
    for i := 1 to Length(str) do

    begin

        if ('0' <= str[i]) and (str[i] <= '9') then

        begin

            j := Integer(str[i]) - Integer('0');

            Inc(cnt[j]);

        end;

    end;
    for i := 0 to 9 do

        Writeln(Format('"%d" : %d', [i, cnt[i]]));

end;
begin

    main;

end.

実行結果



S:\>lesson074\Project1.exe

"0" : 0

"1" : 2

"2" : 2

"3" : 3

"4" : 2

"5" : 3

"6" : 2

"7" : 1

"8" : 2

"9" : 3

Perl

@cnt = (0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
$str = "3.1415926535897932846";

foreach $char(split(//, $str))
{
    $cnt[$char]++ if (("0" le $char) && ($char le "9"));
}

$i = 0;
foreach $char(@cnt)
{
    printf("'%d' : %d\n", $i++, $char);
}

実行結果



L:\>perl lesson_09_074.pl

'0' : 0

'1' : 2

'2' : 2

'3' : 3

'4' : 2

'5' : 3

'6' : 2

'7' : 1

'8' : 2

'9' : 3

Ruby

cnt = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
str = "3.1415926535897932846"

str.split(//s).each do |char|
    cnt[char.to_i] += 1 if (("0" <= char) && (char <= "9"))
end

cnt.each_with_index do |char, i|
    printf("'%d' : %d\n", i, char)
end

実行結果



L:\>ruby  l:\lesson_09_074.rb

'0' : 0

'1' : 2

'2' : 2

'3' : 3

'4' : 2

'5' : 3

'6' : 2

'7' : 1

'8' : 2

'9' : 3