2- link-list.ppt
- 1. Link List • Arrangement of data in memory • There are different ways to arrange data in memory , • Array store data sequentially and in cotigious memory locations that is not either possible nor efficient in large computer system as – There should not be enough memory , but there may be enough blocks – Array is static data structure – Access is slow • To overcome these problems we use link list
- 2. What is link list – linked list is a data structure that consists of a sequence of data records such that in each record there is a field that contains a reference (i.e., a link) to the next record in the sequence. – In link list data is arrange in records • Each record is called node • Data item may be store anywhere in memory • Each node consist of data and pointer to next item • Mean the items are connected logically
- 3. Advantages of link list • Dynamically allocated data structures can be linked together to form a chain. • A linked list is a series of connected nodes (or links) where each node is a data structure. • A linked list can grow or shrink in size as the program runs. • because the nodes in a linked list are dynamically allocated.
- 4. Single link list – Singular link list • Linear collection of data items • Visiting the elements be from start side to end side • Y this is called one way link list • Each node consist of two nodes ,first contain data and the second contain the pointer to next • The last node consist pointer NULL while start variable contain address of first element ,it is also called list pointer variable
- 5. Link list
- 6. Link list operations • The important operations are • Traversing – It is visited form start to end when NULL occur ,so visiting each element is called traversing • Insertion – How to insert a new item in list , at beginning ,at the End , and it Middle • Deletion – How to Delete an item in list , at beginning ,at the End , and it Middle • Searching – To search for an item in the list. • Sorting – So sort the elements in an order…
- 7. Representation in Memory • The items of link list are stored in memory in scattered form but these are linked through pointers • Each item is called an object ,while each object contain at least two fields ,one for to store the data while other one is for next node address
- 8. Circular link list • A link list in which the last node of the list points back to the first node of the list is called circular link list
- 9. Double Link list • A list in which each node has the address both of next and previous node is called Double Link list • It can be visited in both directions • In singular list we can’t go back from current node to previous node .while we can in double l.list • Its also called two way list • Each node consist of three field • One store the data • 2nd store the address of previous node • 3rd store the address of next node
- 11. Double Link list operations • The important operations are • Traversing – It is visited form start to end when NULL occur ,so visiting each element is called traversing ,we do in both directions • Insertion – How to insert a new item in list , at beginning ,at the End , and it Middle • Deletion – How to Delete an item in list , at beginning ,at the End , and it Middle • Searching – To search for an item in the list as array • Sorting – So sort the elements in an order…
- 12. • Operation Name Description • createList() Create a new list (presumably empty) • copy() Set one list to be a copy of another • clear(); Clear a list (remove all elements) • insert(X, ?) Insert element X at a particular position in the list • remove(?) Remove element at some position in the list • get(?) Get element at a given position • update(X, ?) Replace the element at a given position with X • find(X) Determine if the element X is in the list • length() Returns the length of the list.
- 13. • Functions Description • start() Moves the “current” pointer to the very first element • tail() Moves the “current” pointer to the very last element • next() Move the current position forward one element • back() Move the current position backward one element