Consider an array X that contains n positive integers. A subarray of X is defined to be a sequence of array locations with consecutive indices.

The C code snippet given below has been written to compute the length of the longest subarray of X that contains at most two distinct integers. The code has two missing expressions labelled (P) and (Q).

int first=0, second=0, len1=0, len2=0, maxlen=0;
for (int i=0; i < n; i++) {
  if (X[i] == first) {
    len2++;
    len1++;
  } else if (X[i] == second) {
    len2++;
    len1 = (P);
    second = first;
  } else {
    len2 = (Q);
    len1 = 1;
    second = first;
  }
  if (len2 > maxlen) {
    maxlen = len2;
  }
  first = X[i];
}

Which one of the following options gives the CORRECT missing expressions?

(Hint: At the end of the i-th iteration, the value of len1 is the length of the longest subarray ending with X[i] that contains all equal values, and len2 is the length of the longest subarray ending with X[i] that contains at most two distinct values.)

Consider the following program:

int main ( ) { f1( ); f2(2); f3( ); return (0); }	int f1( ) { return (1); }	int f2 (int X) { f3( ); if (X==1) return f1 ( ); else return (X*f2(X$$-$$1)); }	int f3( ) { return (5); }

Which one of the following options represents the activation tree corresponding to the main function?

What is printed by the following ANSI C program?

 #include <stdio.h>
 int main(int argc, char *argv[]) {
    char a = 'P';
    char b = 'x';
    char c = (a & b) + '*';
    char d = (a | b) - '-';
    char e = (a ^ b) + '+';
    printf("%c %c %c\n", c, d, e);
    return 0;
 }

ASCII encoding for relevant characters is given below :

Consider the following pseudo code, where x and y are positive integers.

begin 
    q := 0 
    r := x 
   while r ≥ y do 
      begin 
      r := r - y 
      q := q + 1 
    end 
end

The post condition that needs to be satisfied after the program terminates is