#include <stdio.h>

 #include <string.h>

 /*

 1.以字符串作为参数

 2.找出ASCII在1~127范围内的字符

 3.去掉重复字符

 */

 int GetString(char *str);

 int main(int argc, char *argv[])

 {

     char ch[] = "abcd123123123123123123";

     int num = ;

     num = GetString(ch);

     printf("num = %d\n", num);

     return ;

 } 

 int GetString(char *str)

 {

     /*第一步：先计算符合范围的ASCII*/

     unsigned int index;

     unsigned int n = ;

     unsigned int i = , j, k = ;

     char flag;

     char arr[strlen(str)];

     char newchar[strlen(str)];

     for(index = ; index < strlen(str); index++)

     {

         if((str[index] >= ) && (str[index] <= ))

         {

             arr[n] = str[index];

             n++;

         }

     } 

     while(arr[i] != '\0')

     {

         flag = ;

         for(j = ; j < i; j++)

         {

             if(arr[i] == newchar[j])

             {

                 flag = ;

             }

         }

         if(flag)

         {

             newchar[k] = arr[i];

             k++;

         }

           i++;

     }    

     newchar[k]='\0';

     puts(newchar);  

     return k;

 }