# Data Structures - Interview Questions and Answers

What are the notations used in Evaluation of Arithmetic Expressions using prefix and postfix forms?

Polish and Reverse Polish notations.

Convert the expression ((A + B) * C - (D - E) ^ (F + G)) to equivalent Prefix and Postfix notations.

**Prefix Notation:** - * +ABC ^ - DE + FG
**Postfix Notation:** AB + C * DE - FG + ^ -

Sorting is not possible by using which of the following methods? (Insertion, Selection, Exchange, Deletion)

**Sorting is not possible in Deletion.** Using insertion we can perform insertion sort, using selection we can perform selection
sort, using exchange we can perform the bubble sort (and other similar sorting methods). But no sorting method can be done just using deletion.

What are the methods available in storing sequential files ?

- Straight merging,
- Natural merging,
- Polyphase sort,
- Distribution of Initial runs.

List out few of the Application of tree data-structure?

- The manipulation of Arithmetic expression,
- Symbol Table construction,
- Syntax analysis.

List out few of the applications that make use of Multilinked Structures?

- Sparse matrix,
- Index generation.