31) Which of the following data structure may give overflow error,even though the current number of element in it is less than its size?

32) Number of ADD and REMOVE operations required to access n/2th elements of a queue of n elements so that the original queue remain the same after the access is (take help of another queue.)

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

34) Queue can be used to implement

35) The data structure required to evaluate a postfix expression is