Singly linked list.pptx
- 1. DATA STRUCTURES Santhiya S Assistant Professor Department of AI Kongu Engineering College Code implementation of Singly Linked List
- 2. INSERTING A VALUE IN A LINKED LIST There are three ways of inserting a node in a linked list they are: • Insert at the beginning • Insert at the middle • Insert at the end
- 3. #include<stdio.h> #include<stdlib.h> void display(); int length(); void insert_begin(); void insert_middle(); void insert_end(); void delete(); void delete_end(); struct node { int data; struct node* next; }; struct node* head; void main() { int n,i=0; printf("enter number of element to insert:"); scanf("%d",&n); while(i<n) { insert_begin (); i++; } while(i<n) { insert_end(); i++; } insert_middle(); delete(); delete_end(); display(); length(); } void display() { struct node* p; p=head; while(p!=NULL) { printf("%d->%pn",p->data,p->next); p=p->next; } } int length() { int count=0; struct node* temp; temp=root; while(temp!=NULL) { count++; temp=temp->next; } return count; }
- 4. void insert_begin() { struct node* newnode; newnode=(struct node*)malloc(sizeof(struct node)); printf("enter datan"); scanf("%d", &newnode->data); newnode->next=NULL; if(head==NULL) { head=newnode; } else { newnode->next=head; head=newnode; } } *newnode 100 100 *newnode 35 NULL head if NULL==NULL True 100 200 200 *newnode 45 NULL if 100==NULL False, else block will be executed 100 head 200 300 55 NULL 300 *newnode if 200==NULL False else block will be executed 200 head 300
- 5. void insert_end() { struct node* newnode; newnode=(struct node*)malloc(sizeof(struct node)); printf("enter datan"); scanf("%d", &newnode->data); newnode->next=NULL; if(head==NULL) { head=newnode; } else { struct node* temp; temp=head; while(temp-> next!=NULL) { temp=temp->next; } temp->next=newnode; } } *newnode 100 100 *newnode 35 NULL temp if NULL==NULL True 100 200 200 *newnode 45 NULL if 100==NULL False, else block will be executed 100 head 300 55 NULL 300 *newnode if 100==NULL False else block will be executed 200 300 while NULL!=NULL False while 200!=NULL True temp 200 while NULL!=NULL False
- 6. INSERT AT THE MIDDLE void insert_middle() { struct node *newnode, *p; int loc,len, i=1; printf(“Enter location”); scanf(“%d”,&loc); len=length(); if(loc>len) { printf(“Invlaid Location”); printf(“Currently list is having %d node”,len); } else { p=head; while(i<loc) { p=p->next; i++; } } newnode = (struct node *) malloc (sizeof(struct node)); scanf("%d",&newnode->data); newnode->next=NULL; newnode->next=p->next;(right side) p->next=newnode;(left side) } 94 Nul l 500 head 27 200 100 45 300 200 20 500 300 len *p 1 loc *newnode i 3 loc 3>4 if 100 100 *p while(1<3) 200 *p 2 while(2<3) 300 *p 3 while(3<3) False 450 450 *newnode 35 35 NU LL 35 NU LL 450 35 500 450 450 head 27 200 100 45 300 200 100 20 450 300 35 500 450 94 Nul l 500 4
- 7. DELETING A VALUE IN A LINKED LIST There are three ways of deleting a node in a linked list they are: 1) Delete at the beginning 2) Delete at the middle 3) Delete at the end
- 8. DELETE AT THE BEGINING void delete() { struct node *temp; int loc, len; printf(“Enter location”); scanf(“%d”,&loc) len=length(); if(loc>len)||(head==NULL) { printf(“Invalid Location or empty list); } else if(loc==1) { temp=head; head=temp->next; (left side connection lost) temp->next=NULL; (right side connection lost) free(temp); } temp loc len 1 3 if(1>3)||(100==NULL) False else if(1==1) True head 27 200 100 45 300 200 100 20 NU LL 300 100 temp temp->next=200 200 27 NULL DELETE AT THE BEGINING
- 9. DELETE AT THE MIDDLE else { struct node *p,*q; p=head; int i=1; while(i<loc-1) { p=p->next; i++; } q=p->next; p->next=q->next;(left side connection lost) q->next=NULL; (right side connection lost) free(q); } } head 27 200 100 45 300 200 100 20 450 300 35 500 450 94 Null 500 p *q 100 1 i while(1<2)True 100 *p p 200 while(2<2)False q 300 45 450 2 P->next=300 q->next=450 20 0
- 10. DELETE AT THE END void delete_end(); { struct node*p,*q; p=head; while(p->next!=NULL) { q=p; p=p->next; } q->next=NULL; free(p); } 27 200 100 200 100 300 35 500 450 94 Null 500 p 100 q 100 45 300 20 450 200!=NULL True p 200 300!=NULL True 450!=NULL True q 200 p 300 500!=NULL True q 300 p 450 NULL!=NULL False q 450 p 500 35 NULL