Presentation1.pptx

Presentation1.pptx

• 1.
  Creating a Linkedlist : Algorithm : Create first node and assign the address of the first node to the pointer ‘start’. Step : 1 start =getnode( ); Use another pointer to store the address of the first node, called CURRPTR Step : 2 currptr=Start; Accept the item and store it in the INFO field of the node Step : 3 info[currptr ]= item; Accept the Choice from the keyboard whether to create another node or not Step : 4 if ( choice = ‘Y’) goto step 5 else goto step 6 If choice is ‘Y’ to create another node
• 2.
  Step : 5i) Newnode = getnode( ); Newnode which contains the address of the newly created node ii) link[currptr]=Newnode; Making a link between the original last node and present newnode iii) currptr=Newnode; Address of the Newnode is assigned to the original newnode iv) info[currptr]=item; Accepting the item and storing it in the info field of currptr go to step 4 If choice is ‘N’ to make the LINK field of the last node to NULL Step : 6 link [currptr] = NULL and Exit Step : 7 return
• 3.
  • Traversing alinked list : Algorithm: Step 1 : Is linked list is empty if ( start ==NULL) display (“ linked list is empty “); exit( ) Step 2 : Assign start value to CURRPTR currptr=start; Step 3 : Repeat while(currptr!=NULL) Process info[currptr] Step 4 : currptr=link[currptr] /* moving the currptr from one node to the next node */ Step 5 : Exit
• 4.
  • Algorithm forDisplaying a list : • first check list is empty or not • Step 1 : if ( start == NULL) – Write (“ list is Empty”) – return; Store the Address of first node in another pointer CURRPTR • Step 2 : set currptr = start; • Step 3 : Repeat step4 and step5 while ( currptr !=NULL) • Display items one-by-one from first node until Currptr becomes NULL • Step 4 : display ( info[currptr]); After the display of this element ,Currptr should point to the next node • Step 5 : currptr=link[currptr]; • Step 6 : Exit
• 5.
  • Insert operationat the beginning : • Algorithm : • Creating a node that is to be inserted • step 1 : Newnode =getnode( ); • Enter the item into the Info field of the New node • step 2 : info [Newnode]= item; • Assign the start value to the LINK part of the inserted node(New node). • It makes a link from ‘New node’ to the previous first node. • Now start and New node points to the original first node of the list. • It makes link between start and Newnode. • step 3 : link [Newnode]=start; • step 4 : start = Newnode; Exit;
• 6.
  • Algorithm :insert operation at end Step 1 : if list is empty if ( start == NULL) insert at the beginning exit( ) end if Step 2 : currptr = start; Traverse the list to obtain the last node address Step 3 : while (link [currptr]! = NULL) currptr = link [ currptr] end while Create a newnode and enter the accepted ITEM into its INFO fields Step 4 : Newnode =getnode( ); Newnode -> info =item; Make a link between Currptr(last node) and New node Step 5 : link [currptr] = Newnode; Step 6 : link [Newnode] = NULL Step 7 : Exit
• 7.
  • Algorithm forInserting at certain position : Step 1: Set CURRPTR to Start Currptr=Start Step 2: If the item is to be inserted at 1st position if (pos==1) Algorithm for inserting at beginning Else go to step 3 Step 3: If the item to inserted at some position other than 1st position for ( i=0; i < pos-2;i++) { Currptr= LINK[Currptr] } Step 4: Create a Newnode Newnode=getnode();
• 8.
  Step 5: Enterthe element in the INFO field of Newnode INFO[Newnode]=ITEM; Step 6: Make a connection between the Newnode and the next node after CURRPTR LINK[Newnode]=LINK[Currptr] Step 7: Make a link between Currptr and newnode LINK[Currptr]=Newnode; Step 8 : Exit
• 9.
  • Delete anode from the beginning: • Algorithm: Step 1 : check whether the list is empty if ( start==NULL) • write “ linked list is empty” • else goto step 2 Step 2 : Set Currptr to start Currptr=start; Step 3 : Assign the link field of the first node to ‘start’ to delete the original first node start = link[start]; Step 4 : Free the deleted item free(Currptr); Step 5 : Exit
• 10.
  • Delete anode At the end: • Algorithm: Step 1 : check whether the list is empty if ( start==NULL) • write “ linked list is empty” • else goto step 2 Step 2 : check if the list has only one element if ( Link[start]==NULL) then start=NULL; else goto step 4 Step 3 : free the deleted node free(start); Step 4 : Assign start value to Currptr Currptr=start; Step 5 : Assign NULL to the another pointer PREVPTR PREVPTR = NULL
• 11.
  Step 6 :Traverse the list until the Currptr points to last node and PREVPTR points to the last before node While(Link[Currptr]!=NULL) { PREVPTR=Currptr; Currptr = Currptr -> link; Step 7 : To make the LINK part of the last node, after deletion to NULL PREVPTR->LINK=NULL Step 8 : Exit
• 12.
  • Delete anode at the given position: • Algorithm:  Step 1: Check for the position whether the deletion is at first position if ( pos==1) Algorithm for deleting a node at beginning else goto Step 2  Step 2 : Set Currptr to Start Currptr=start  Step 3: set PREVPTR to NULL PREVPTR = NULL Step 4 : if the item to be deleted is not at first position for ( i=1; i<pos; i++ ) { PREVPTR=Currptr; Currptr = Currptr->link }
• 13.
  •  Step5 : LINK of PREVPTR is assigned with Link of Currptr i.e. … make a link between the PREVPTR and the next node of Currptr PREVPTR  Link = Currptrlink Step 6 : Exit
• 14.
  • Searching ina single linked list • Algorithm : • Step 1: set Currptr=start LOC = NULL • Step 2: Repeat step 3 while (Currptr !=NULL) • Step 3: if (item == Info [Currptr] ) – Then LOC = Currptr – And display “ Search Successful “ – Exit – else – Currptr = Link [ Currptr ] [ so Currptr, Now points to the next node ] • Step 4: if LOC = NULL Display “ Search unsuccessful “ • Step 5 : Exit
• 15.
  • Garbage Collection: Garbagecollection is the automatic reclamation of computer storage The GC function is to find data objects that are no longer in use and make their space available by the running program. So Why Garbage Collection: A software routine operating on data structure should not have to depend what other routines may be operating on the same structure. If the process does not free used memory the unused space is accumulated until the process terminates. Garbage collection is considered cheaper than explicit deal location A good garbage collector shows a program down by factor of 10 percent. Although it seems a lot , it is only a small price to pay for : Convenience Development time Reliability