hdu 2000 ASCII码排序

#include<stdio.h>#include<stdlib.h>#include<string.h>int cmp(const void *a,const void *b){   return *(char *)a-*(char *)b;}int main(){    int i;    char str[4];    while(~scanf("%s",str))    {       qsort(str,3,sizeof(str[0]),cmp);       for(i=0;i<2;i++)        printf("%c ",str[i]);        printf("%c\n",str[i]);    }    return 0;}