Which one of the following permutations can be obtained the output using stack assuming that the input is the sequence 1,2,3,4,5 in that order ?

The postfix expression for * + a b - c d is?

• [A] ab + cd - *
• [B] ab cd + - *
• [C] ab + cd * -
• [D] ab + - cd *

The following sequence of operation is performed on stack : push(1),push(2),pop,push(1),push(2),pop,pop,pop,push(2),pop. The sequence of popped out values are ?

• [A] 2,2,1,1,2
• [B] 2,2,1,2,2
• [C] 2,1,2,2,1
• [D] 2,1,2,2,2

The initial configuration of the queue is a,b,c,d (a is the front end). To get the configuration d,c,b,a one needs a minimum of ?

• [A] 2 deletions and 3 additions
• [B] 3 additions and 2 deletions
• [C] 3 deletions and 3 additions
• [D] 3 deletions and 4 additions

Given two sorted lists of size m and n respectively.The number of comparisons needed in the worst case by the merge sort algorithm will be?

• [A] mn
• [B] max(m,n)
• [C] min(m,n)
• [D] m+n-1

What is data structure?