Question

This question is in C++.

For each code snippet below, write what the code outputs to the standard output:

(a) queue < int > q ;

q . push (4);

q . push (7);

q . push (2);

q . push (11);

q . push (16);

for ( int i = 0; i < q . size (); i ++)

{

q . push ( q . front () * 2);

q . pop ();

}

while (! q . empty ()) {

cout << q . front () << " ";

q . pop ();

}

(b) void print_vec ( vector < string > vec , int idx ) {

if ( idx == -1) return ;

print_vec ( vec , idx - 1);

cout << vec [ idx ] << endl ;

}

int main ()

{

vector < string > colors = {" blue " , " yellow " , " green " , " red "};

print_vec ( colors , 3);

return 0;

}

Answer 1

(a) queue < int > q ;
q: []
q . push (4);
q: [4]
q . push (7);
q: [4,7]
q . push (2);
q: [4,7,2]
q . push (11);
q: [4,7,2,11]
q . push (16);
q: [4,7,2,11,16]

Iteration1:
q: [7,2,11,16,8]

Iteration2:
q: [2,11,16,8,14]

Iteration3:
q: [11,16,8,14,4]

Iteration4:
q: [16,8,14,4,22]

Iteration5:
q: [8,14,4,22,32]

while loop prints the content of array by removing each value from queue q
So, It prints
8 14 4 22 32

===========================================

(b)
This code passed the vector to function.
This function prints the content of array in the same order in vector
So, output is
 blue
 yellow
 green
 red