DS-UNIT-2-Stack Queue

In a stack, if a user tries to remove an element from an empty stack it is called _________

• Underflow

• Empty collection

• Overflow

• Garbage Collection

Assume that the operators +, -, × are left associative and ^ is right associative. The order of precedence (from highest to lowest) is ^, x , +, -. The postfix expression corresponding to the infix expression a + b × c - d ^ e ^ f is

• abc × + def ^ ^ -

• abc × + de ^ f ^ -

• ab + c × d - e ^ f ^

• + a × bc ^ ^ def

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

• 284

• 213

• 142

• 71

If the elements "A", "B", "C" and "D" are placed in a queue and are deleted one at a time, in what order will they be removed?

• ABCD

• DCBA

• DCAB

• ABDC

A normal queue, if implemented using an array of size MAX_SIZE, gets full when?

• Rear = MAX_SIZE - 1

• Front = (rear + 1)mod MAX_SIZE

• Front = rear + 1

• Rear = front

How many stacks are needed to implement a queue. Consider the situation where no other data structure like arrays, linked list is available to you.

• 1

• 2

• 3

• 4

Which of the following is NOT a common operation in a queue data structure?

• Enqueue

• Dequeue

• Peek

• Shuffle

How many stacks are needed to implement a queue. Consider the situation where no other data structure like arrays, linked list is available to you.

• 1

• 2

• 3

• 4

Suppose a circular queue of capacity (n – 1) elements is implemented with an array of n elements. Assume that the insertion and deletion operation are carried out using REAR and FRONT as array index variables, respectively. Initially, REAR = FRONT = 0. The conditions to detect queue full and queue empty are

• Full: (REAR+1) mod n == FRONT, empty: REAR == FRONT

• Full: (REAR+1) mod n == FRONT, empty: (FRONT+1) mod n == REAR

• Full: REAR == FRONT, empty: (REAR+1) mod n == FRONT

• Full: (FRONT+1) mod n == REAR, empty: REAR == FRONT

If the sequence of operations - push (1), push (2), pop, push (1), push (2), pop, pop, pop, push (2), pop are performed on a stack, the sequence of popped out values

• 2,2,1,1,2

• 2,2,1,2,2

• 2,1,2,2,1

• 2,1,2,2,2