Consider the following C program:

#include< stdio.h >
void fun1(char *s1, char *s2){
  char *tmp;
  tmp = s1;
  s1 = s2;
  s2 = tmp;
}
void fun2(char **s1, char **s2){
  char *tmp;
  tmp = *s1;
  *s1 = *s2;
  *s2 = tmp;
}
int main(){
  char *str1 = "Hi", *str2 = "Bye";
  fun1(str1, str2); printf("%s %s ", str1, str2);
  fun2(&str1, &str2); printf("%s %s", str1, str2);
  return 0;
}

The output of the program above is

Consider the following C program.

#include< stdio.h >
struct Ournode{
 char x,y,z;
};
int main(){
 struct Ournode p = {'1', '0', 'a'+2};
 struct Ournode *q = &p;
 printf ("%c, %c", *((char*)q+1), *((char*)q+2));
 return 0;
}

The output of this program is:

The set of all recursively enumerable languages is

Let $$N$$ be an $$NFA$$ with $$n$$ states. Let $$k$$ be the number of states of a minimal $$DFA$$ which is equivalent to $$N.$$ Which one of the following is necessarily true?