C++经典算法题-输入一行字符，分别统计出其中英文字母、空格、数字和其它字符的个数

#include "stdio.h"

    main()
    {char c;
        int letters=0,space=0,digit=0,others=0;
        printf("please input some characters\n");
        while((c=getchar())!='\n')
        {
            if(c>='a'&&c<='z'||c>='A'&&c<='Z')
                letters++;
            else if(c==' ')
                space++;
            else if(c>='0'&&c<='9')
                digit++;
            else
                others++;
        }
        printf("all in all:char=%d space=%d digit=%d others=%
                d\n",letters,space,digit,others);
    }