Data Structure


Q241.

Assume that the operators +, -, \times are left associative and \hat{} is right associative. The order of precedence (from highest to lowest) is \hat{}, \times, +, -. The postfix expression corresponding to the infix expression a+ b \times c-d \;\; \hat{} e \; \; \hat{} \; \; f is
GateOverflow

Q242.

The five items: A, B, C, D, and E are pushed in a stack, one after other starting from A. The stack is popped four items and each element is inserted in a queue. The two elements are deleted from the queue and pushed back on the stack. Now one item is popped from the stack. The popped item is
GateOverflow

Q243.

The five items: A, B, C, D, and E are pushed in a stack, one after other starting from A. The stack is popped four items and each element is inserted in a queue. The two elements are deleted from the queue and pushed back on the stack. Now one item is popped from the stack. The popped item is
GateOverflow

Q244.

Choose the correct alternatives (more than one may be correct) and write the corresponding letters only: The following sequence of operations is performed on a stack: PUSH (10), PUSH (20), POP, PUSH (10), PUSH (20), POP, POP, POP, PUSH (20), POP The sequence of values popped out is
GateOverflow

Q245.

Consider the following C program: #include < stdio.h > #define EOF -1 void push (int); /* push the argument on the stack */ int pop (void); /* pop the top of the stack */ void flagError (); int main () { int c, m, n, r; while ((c = getchar ()) != EOF) { if (isdigit (c) ) push (c); else if ((c == '+') || (c == '*')) { m = pop (); n = pop (); r = (c == '+') ? n + m : n*m; push (r); } else if (c != ' ') flagError (); } printf("% c", pop ()); } What is the output of the program for the following input?5 2 * 3 3 2 + * +
GateOverflow

Q246.

Consider the following sequence of operations on an empty stack. push(54); push(52); pop(); push(55); push(62); s=pop(); Consider the following sequence of operations on an empty queue. enqueue(21); enqueue(24); dequeue(); enqueue(28); enqueue(32); q=dequeue(); The value of s+q is ___________.
GateOverflow

Q247.

Suppose a stack implementation supports an instruction REVERSE, which reverses the order of elements on the stack, in addition to the PUSH and POP instructions. Which one of the following statements is TRUE with respect to this modified stack?
GateOverflow

Q248.

The result evaluating the postfix expression 10 5 + 60 6 / * 8 - is
GateOverflow

Q249.

Choose the equivalent prefix form of the following expression(a+(b-c))^{\star}((d-e) /(f+g-h))
GateOverflow

Q250.

A function f defined on stacks of integers satisfies the following properties. f(\emptyset) = 0 and f (push (S, i)) = max (f(S), 0) + i for all stacks S and integers i. If a stack S contains the integers 2, -3, 2, -1, 2 in order from bottom to top, what is f(S)?
GateOverflow