统计字符串中有多少空格,数字,字母

#include <stdio.h>

int main()
{
    int ch_num = 0;
    int space_num = 0;
    int int_num = 0;
    char ch = getchar();

    while (ch != '\n')
    {
        if (ch==' ')
        {
            space_num++;
        }
        else if ((ch>='a'&&ch<='z') || (ch>='A'&&ch<='Z'))
        {
            ch_num++;
        }
        else if (ch>='0'&&ch<='9')
        {
            int_num++;
        }
        ch = getchar();
    }

    printf ("space_num = %d\nch_num = %d\nint_num = %d\n",space_num,ch_num,int_num);

    return 0;
}