iOS字符串abd和bad兄弟字符串,如何迅速判断两个字符串是兄

int isBrotherStr(char *str1, char *str2){
    int a[26*2] = {0};
    int i;
    unsigned long strLen;
    if (!str1 && !str2) {
        return 1;
    }else if (!str1 || !str2){
        return 0;
    }else{
        if(strlen(str1) != strlen(str2))
            return 0;
        strLen = strlen(str1);
        for(i = 0; i < strLen; i++)
        {
            ++a[str1[i] - 'A'];
            --a[str2[i] - 'A'];
        }
        for(i = 0; i < 26 * 2; i++)
            if (a[i])
                return 0;
        return 1;
    }
    return 0;
}
int main(int argc, const char * argv[]) {
    
    char *str1 = "asdfaabAAB";
    char *str2 = "asdfAABaab";
    if (isBrotherStr(str1, str2))
        printf(" String 1 and String 2 are brothers!");
    else
        printf(" String 1 and String 2 are not brothers!");
    
    
    return 0;
}