# ds by keralaguest

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```									1) What is the difference between Storage structure and file structure?
The representation of a particular data structure in the memory of a computer is called a
storage structure whereas a storage structure representation in auxiliary memory is often
called a file structure.

2) Define data structure in terms of relation?
The possible ways in which the data items or atoms are logically related define different data
structures.

3) State procedure in accordance with function?
A procedure is similar to a function but there is no value returned explicitly. A procedure is
also invoked differently. Where there are parameters, a procedure returns its results through
the parameters

4) Define an addressing function for a data structure?
An addressing function for a data structure consisting of n elements is a function which maps
the ith element of the data structure onto an integer between one and n. In the case of a
vector, the addressing function f maps the ith element onto the integer (i).

5) How do you define a vector for a data structure?
The simplest data structure that makes use of computed address to locate its elements is the
one – dimensional array and is called as a vector.

6) Define stack?
An important sub class of lists permits the insertion or deletion of an element to occur only at
one end. A linear list belonging to this sub class is called a stack.

7) Define and explain “push” and “pop”?
The insertion operation is referred to as “push” and the deletion operation is referred to as
“pop”. Since, insertion and deletion operations are performed at one end of the stack; the
elements can only be removed in the opposite order from that in which they were added to
the stack. This phenomenon is observed in conjunction with recursive functions.

8) Explain the three applications in which stacks are used?
The first application majorly deals with the recursion, the second application is a classical and
the last one is known as stack machines which chiefly deals with insertion and deletion from
the stack.

9) State the theorem which is used to determine whether a given expression is valid or not.
A polish suffix formula is well formed if and only if the rank of the formula is “one” and the
rank of any proper head of a polish formula is greater than or equal to “one”.

10) What is a priority queue?
Waiting queue may not operate on a strictly first in first out basis, but on some complex
priority scheme based on such factors as what compiler is being used, the execution time
required, number of print lines, etc. The resulting queue is called a priority queue.

11) What is linear hashing?
In linear hashing, the table is gradually expanded by splitting the buckets in order until the
table has doubled its size.

12) What is splitting?
Splitting refers to the rehashing of a bucket b and its overflow in order to distribute the keys
in them among b and one other primary location.
13) What is a one way chain or singly linked linear list?
A list has been defined to consist of an ordered set of elements which may vary in number. A
simple way to represent a linear list is to expand each node to contain a link or pointer to the
next time.

14) Name two desirable properties of hashing functions.
Some of the desirable properties of a hashing function are speed and the generation of

15) What is the distant relationship between a list structure and a digraph?
In particular, a list is a directed graph with one source node corresponding to the entire list
and with every node immediately connected to the source code.

16) Define Simulation?
Simulation is the process of forming an abstract model from a real situation in order to
understand the impact of modifications and the effect of introducing various strategies on the
situation.

17) Define Index area and its subdivisions?
Index area is created automatically by the data-management routines in the operating
systems. A number of index levels may be involved in an indexed sequential file. The lowest of
index is the track index, which is always written on the first track of the cylinders for the
indexed sequential file. The track index contains two entries for each prime track of the
cylinder a normal entry and an overflow entry.

18) Given N discs of decreasing size stacked on one needle and two empty needles, it is
required to stack all the discs onto a second needle in decreasing order of size. The third
needle may be used as temporary storage.
The movement of the discs is restricted by the following rules
(1) A disc may be moved from any needle to any other
(2) Only one disc may be moved at a time
(3) At no time may a larger disc rest upon smaller disc explain the solution?
Ans) The solution to this problem is most clearly seen with the aid of induction, to move one
disc, merely move it from needle A to needle C. To move two discs, move the first disc to
needle B, move the second from needle A to needle C, then move the disc from needle B to
needle C.

There are many data structures which can be represented so as to permit the referencing of
any element by knowing its position in the structure. The selection operation associated with
such a structure is said to possess an addressing function. An addressing function for a data
structure consisting of n elements is a function which maps the ith element of the data
structure onto an integer between one and n. In the case of a vector, the addressing function f
maps the ith element onto the integer I, which is a linear addressing function.

20) What exactly does this procedure BUBBLE_SORT (K, N) does?
Given a vector K of N elements, this procedure sorts the elements into ascending order using
the method just described. The variables PASS and LAST denote the pass counter and position
of the last unsorted elements respectively. The variable I is used to index the vector elements.
The variable EXCHS is used to count the number of exchanges made on any pass. All variables
are integer.

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