C语言字符统计：字母、数字、空格和其他

#include <stdio.h>

int main()
{
    char c;
    int letter = 0, digit = 0, space = 0, other = 0;

    printf("请输入若干字符，以*结束：\n");
    while ((c = getchar()) != '*') {
        if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z')) {
            letter++;
        } else if (c >= '0' && c <= '9') {
            digit++;
        } else if (c == ' ') {
            space++;
        } else {
            other++;
        }
    }

    printf("字母字符：%d，数字字符：%d，空格：%d，其他：%d\n", letter, digit, space, other);

    return 0;
}