题解 | 判断是不是字母

#include <stdio.h>

int main() {
    char letter = 0;
    while (scanf("%c", &letter) != EOF) {
        getchar();//吃掉上次输入后的回车
        if (
            (letter >= 65 && letter <= 90)|| 
            (letter >= 65 + 32 && letter <= 90 + 32)
        ) {
            printf("%C is an alphabet.\n", letter);
        }
        else {
            printf("%C is not an alphabet.\n", letter);
        }    
    }
    return 0;
}