Singly Linked List Data Structures PDF

# Insertion in Singly Linked List ## Insert at Beginning * **Code:** ```c struct node { int data; struct node *next; }; struct node *head, *newnode; newnode = (struct node *)malloc(sizeof(struct node)); printf("Enter data u want to insert: "); scanf("%d", &new_node->data); ne...

# Insertion in Singly Linked List ## Insert at Beginning * **Code:** ```c struct node { int data; struct node *next; }; struct node *head, *newnode; newnode = (struct node *)malloc(sizeof(struct node)); printf("Enter data u want to insert: "); scanf("%d", &new_node->data); newnode->next = head; head = newnode; ``` * **Example:** - Before: `head 500 -> 7/200 -> 1/300 -> 9/0` - After: `head 400 -> 7/200 -> 1/300 -> 9/0 ` - Newnode `2/100 -> 500` ## Insert at the End * **Code:** ```c struct node { int data; struct node *next; }; struct node *head, *newnode, *temp; newnode = (struct node *)malloc(sizeof(struct node)); printf("Enter data u want to insert: "); scanf("%d", &newnode->data); newnode->next = 0; temp = head; while(temp->next != 0) { temp = temp->next; } temp->next = newnode; ``` * **Example:** - Before: `head 100 -> 7/200 -> 1/300 -> 9/300` - After: `head 100 -> 7/200 -> 1/300 -> 9/300 -> 5/400` - Newnode `5/400 -> 0'` - The code `newnode->next = 0` ensures that the new node now points to null - We must traverse the entire list so we use `temp`. ## Insertion after a given Location * **Code:** ```c int pos; struct node { int data; struct node *next; }; struct node *head, *newnode, *temp; newnode = (struct node *)malloc(sizeof(struct node)); printf("Enter the position: "); scanf("%d", &pos); if(pos > count) { printf("Invalid Position"); } else { temp = head; while(i < pos) { temp = temp->next; i++; } printf("Enter data"); scanf("%d", &newnode->data); newnode->next = temp->next; temp->next = newnode; } ``` * **Example:** - Before: `head 100 -> 7/200 -> 1/300 -> 9/300` - After: `head 100 -> 7/200 -> 1/300 -> 5/200 -> 9/300 ` - Newnode `5/200 -> 9/300` # Deletion from Beginning * **Code:** ```c head temp { free(temp); temp = head; head = head->next; free(temp); } ``` * **Example:** - Before: `head 100 -> 5/200 -> 3/300 -> 9/400 -> 1/100` - After: `head 5/200 -> 3/300 -> 9/400 -> 1/100` # Deletion from End * **Code:** ```c // initially prevnode and temp point to head while(temp->next !=0) { prevnode = temp; temp = temp->next; } prevnode -> next = 0; free(temp); ``` * **Example:** - Before: `head 200 -> 3/300 -> 9/400 -> 1/100` - After: `head 200 -> 3/300 -> 9/400` # Searching a Node in Singly Linked List * **Code:** ```c int flag = 0; printf("Enter key element "); scanf("%d", &key); temp = head; while(temp != NULL) { if(key == temp->data) { flag = 1; break; } temp = temp->next; } if (flag == 1) { printf("Key elements found"); } else { prinf("Key element nor found"); } ``` * **Example:** - Before: `head 100 -> 5/200 -> 6/300 -> 7/100` - Search for key = 6; - Result: Key element found # Traversing in a Linked List * **Code:** ```c struct node { int data; struct node *next; }; struct node *head, *temp; traverse() { if(head == NULL) { printf("L.L. is Empty"); } struct node *temp = NULL; temp = head; while(temp != NULL) { printf("%d", temp->data); temp = temp->next; } } ``` * **Example:** - Before: `head 100 -> 5/200 -> 6/300 -> 7/100` - Result: Print the following: 100, 200, 300, 100 # Doubly Linked List - **Features:** - **Forward and Backward:** Can traverse in both directions - **Temp Pointer:** Can look forward and backward - **Drawback:** Stores two pointers, which requires more memory space.