401 - Palindromes

#include <stdio.h>
#include <stdlib.h>
#include <string.h>


char charachter[21] = {'A','E','H','I','J','L','M','O','S','T','U','V','W','X','Y','Z','1','2','3','5','8'};
char reverse_[21] = {'A','3','H','I','L','J','M','O','2','T','U','V','W','X','Y','5','1','S','E','Z','8'};
int isPalindrome(char *str){
    int i, len = strlen(str);
    for(i = 0 ; i < len/2 ; i++)
        if(str[i] != str[len - i - 1])
            return 0;
    return 1;
}

int isMirrored(char *str){
    int indx1, indx2 ,i, len = strlen(str);
    for(i = 0 ; i < len/2; i++){
        indx1 = indx2 = 0;
        while(charachter[indx1] != str[i] && indx1 < 21)
            indx1++;
        while(reverse_[indx2] != str[len - i - 1] && indx2 < 21)
            indx2++;
        if(indx1 != indx2)
            return 0;
    }
    return 1;
}

int main()
{
    char str[21];
    int x,y;
    while(scanf("%s",str)!= EOF ){
    x = isPalindrome(str);
    y = isMirrored(str);
    if(x == 0 && y == 0)
        printf("%s -- is not a palindrome.\n\n",str);
    else if(x==1 && y == 0)
            printf("%s -- is a regular palindrome.\n\n",str);
    else if(x == 0 && y == 1)
            printf("%s -- is a mirrored string.\n\n",str);
    else
        printf("%s -- is a mirrored palindrome.\n\n",str);
    }
    return 0;
}