Consider the C function foo and the binary tree shown.

typedef struct node {
    int val;
    struct node *left, *right;
} node;
int foo(node *p) {
    int retval;
    if (p == NULL)
        return 0;
    else {
        retval = p->val + foo(p->left) + foo(p->right);
        printf("%d ", retval);
        return retval;
    }
}

When foo is called with a pointer to the root node of the given binary tree, what will it print?

Consider a sequence a of elements $$a_0=1,a_1=5,a_2=7,a_3=8,a_4=9$$, and $$a_5=2$$. The following operations are performed on a stack S and a queue Q, both of which are initially empty.

I: push the elements of a from a$$_0$$ to a$$_5$$ in that order into S.

II: enqueue the elements of a from a$$_0$$ to a$$_5$$ in that order into Q.

III: pop an element from S.

IV: dequeue an element from Q.

V: pop an element from S.

VI: dequeue an element from Q.

VII: dequeue an element from Q and push the same

VIII: Repeat operation VII three times.

IX: pop an element from S.

X: pop an element from S.

The top element of S after executing the above operations is ____________.

Which one of the options given below refers to the degree (or arity) of a relation in relational database systems?

Consider the following table named Student in a relational database. The primary key of this table is rollNum.

Student

The SQL query below is executed on this database.

SELECT *

FROM Student

WHERE gender = 'F' AND

marks > 65;

The number of rows returned by the query is _____________.