#include <ctype.h> #include <stdio.h> int main() { char a; while (scanf("%c", &a) != EOF) { // 注意 while 处理多个 case // 64 位输出请用 printf("%lld") to getchar(); if(isalpha(a)) { printf("%c is an alphabet.\n",a); } else { printf("%c is not an alphabet.\n",a); } } return 0; }