#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int main (void)
{
        int i = 0;
        char alphabet[27];
        char tmp = 'a';
        for (i=0;i<26;i++)
        {
        //printf("%c",tmp);
        strcat(alphabet,tmp);
        tmp++;
        fflush(stdin);
        }
        printf("%s",alphabet);
        printf("\n");

}

Output :

inazad@neomatrix-jr:~/Desktop/tmp/md5-main$ gcc atoz.c -o atoz
atoz.c: In function «main":
atoz.c:12: attention : passing argument 2 of «strcat" makes pointer from integer without a cast