//读入字符串，并排序字符串

 #include <stdio.h>

 #include <string.h>

 #define SIZE 81

 #define LIM 20

 #define HALT ""

 void stsrt(char * strings [], int num); //字符串排序函数

 char * s_gets(char * st,int n);

 int main(void)

 {

     char input[LIM][SIZE];

     char *ptstr[LIM];

     int ct =;

     int k;

     printf("Input up to %d lines,and I will sort them.\n",LIM);

     printf("To stop,press the Enter key at a line's start.\n");

     while(ct<LIM && s_gets(input[ct],SIZE)!= NULL && input[ct][]!='\0')

     {

         ptstr[ct] = input[ct]; //设置指针指向字符串

         ct++;

     }

     stsrt(ptstr,ct); //字符串排序函数

     puts("\nHere's the sorted list:\n");

     for (k=;k<ct;k++)

         puts(ptstr[k]);

     return ;

 }

 void stsrt(char *strings [], int num)

 {

     char *temp;

     int top,seek;

     for(top=;top <num -;top++)

         for(seek=top+;seek<num;seek++)

             if(strcmp(strings[top],strings[seek])>)

             {

                 temp = strings[top];

                 strings[top] = strings[seek];

                 strings[seek] = temp;

             }

 }

 char * s_gets(char * st, int n)

 {

     char * ret_val;

     int i=;

     ret_val = fgets(st, n, stdin); //读取成功，返回一个指针，指向输入字符串的首字符；

     if(ret_val)

     {

         while(st[i]!='\n' && st[i]!='\0')

             i++;

         if(st[i] =='\n') //fgets会把换行符也吃进来了，fgets会在末尾自动加上\0;

             st[i]='\0';

         else   //其实是'\0'

             while(getchar() != '\n')  //会把缓冲区后续的字符都清空

                 continue;

     }

     return ret_val;

 }