A priority queue Q is used to implement a stack that stores characters. PUSH (C) is implemented INSERT (Q, C, K) where K is an appropriate integer key chosen by the implementation. POP is implemented as DELETEMIN(Q). For a sequence of operations, the keys chosen are in

The postfix expression for the infix expression A + B * (C + D) / F + D * E is:

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

The following sequence of operations is performed on stack: PUSH (10),PUSH (20),POP,PUSH (10),PUSH (20),POP,POP,POP,PUSH (20),POP The sequence of the value popped out is: