程序代码:#include <stdio.h>
#include <string.h>
void main()
{ char s1[200],s2[200]="",*a;
int i,j;//,k=1,l=0;
printf("请输入字符串:");
gets(s1);
s2[0]=s1[0];
for(i=0,j=1;s1[i]!='\0';i++)
{
a=strchr(s2,s1[i]);
if(a==NULL)
{ s2[j++]=s1[i];
s2[j]='\0';
}
}
s2[j]='\0';
puts(s2);
}









