1 The logical and mathematical model of a particular organization of data is called data structure. There are two types of data structure Linear Nonlinear
2 The goal of data Structure is ,It must rich enough in structure to reflect the actual relationship of data in real world. The structure should be simple enough for efficient processing of data.
3 Stack is a ordered collection of items Stack is a dynamic object whose size is constantly changing as items are pushed and popped . Stack may contain different data types Stack is declared as a structure containing an array to hold the element of the stack, and an integer to indicate the current stack top within the array.
4 Array is an ordered collection of items Array is a static object i.e. no of item is fixed and is assigned by the declaration of the array It contains same data types. Array can be home of a stack i.e. array can be declared large enough for maximum size of the stack.
5 The definition which defines an object in terms of simpler cases of itself is called recursive definition.
6 In sequential search each item in the array is compared with the item being searched until a match occurs. It is applicable to a table organized either as an array or as a linked list.
7 when a function is called, arguments are passed local variables are allocated and initialized transferring control to the function
8 Actions performed when a function returns, Return address is retrieved Function’s data area is freed Branch is taken to the return address
9 A linked list is a linear collection of data elements, called nodes, where the linear order is given by pointers. Each node has two parts first part contain the information of the element second part contains the address of the next node in the list. The disadvantages of array are, unlike linked list it is expensive to insert and delete elements in the array One can’t double or triple the size of array as it occupies block of memory space. In linked list, each element in list contains a field, called a link or pointer which contains the address of the next element Successive element’s need not occupy adjacent space in memory.
10 we cannot apply binary search algorithm to a sorted linked list, since there is no way of indexing the middle element in the list. This is the drawback in using linked list as a data structure.
11 Pool is a list consisting of unused memory cells which has its own pointer.