#include"stdio.h"

void main()
{
    //char  monday tuesday wednesday thursday friday saturday sunday;
    char x, letter;
    int i;

      printf("请输入字母：\n");
      scanf("%c", &x);
      if(x == 'm')
          printf("Monday\n");
      else if(x == 'w')
          printf("Wednesday\n");
      else if(x == 'f')
          printf("Friday\n");
      else if(x == 't')
      {
       printf("请再输入第二个字母：\n");
       if((letter = getchar())  == 'h')
           printf("Thursday");
       else if((letter = getchar())  == 'u')
           printf("Tuesday");
       else
           printf("error input");
      }
      else if(x == 's')
      {
       printf("请再输入第二个字母：\n");
      
       if((letter = getchar()) == 'u')
           printf("sunday");
       if((letter = getchar()) == 'u')
           printf("saturday");
       else
           printf("error input");
    }
      else
          printf("error input");

}

额、、、肿是啥意思、、、

嗯，这个我已经弄清楚了、、、现在我又发现了一个getchar()的陷阱，帮忙看下 谢了
#include"stdio.h"

void main()
{

    char x, y, z;
    int i;

      printf("请输入字母：\n");
      scanf("%c", &x);
      fflush(stdin);
      if(x == 'm')
          printf("Monday\n");
      else if(x == 'w')
          printf("Wednesday\n");
      else if(x == 'f')
          printf("Friday\n");
      else if(x == 't')
      {
       printf("请再输入第二个字母：\n");
      
       if((y = getchar())  == 'h')
           printf("Thursday");
       else if((y = getchar())  == 'u')
           printf("Tuesday");
       else
           printf("error input");
      }

      else if(x == 's')
      {
       printf("请再输入第二个字母：\n");
      
       if((z = getchar()) == 'u')
           printf("sunday");
       else if((z = getchar()) == 'a')
           printf("saturday");
       else
           printf("error input");
    }
      else
          printf("error input");

}

比如先输入T再输入h会输出thursday
但是先输入t再输入u则会出现error input

那为什么输入t再输入h能输出结果呢？

谔谔、、我弄清楚了，是缓冲区的问题、、、

谢啦 下了