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newnode->next = first;
first= newnode;
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Program for inserting a new node in between two list in c?
To insert a new node between two lists, append the new node to the first list, then insert the head node of the second list after the new node.
Explain any two advantages using Single linked list over Doubly linked list and vice-versa?
Advantages of single linked list: # Decrease in storage space per linked list node # Simpler implementation Advantages of double linked list # Decrease in work when accessing a random node # Decrease in work when inserting or deleting a node
How many pointers will have to be changed if a node is deleted from a linear linked list?
For a singly-linked list, only one pointer must be changed. If the node about to be deleted (let's call it node for the sake of argument) is the head of the list, then the head node pointer must be changed to node->next. Otherwise, the node that comes before the deleted node must change its next pointer to node->next. Note that given a singly-linked node has no knowledge of its previous node, we must traverse the list from the head in order to locate that particular node, unless the node is the head of the list: void remove (List* list, Node* node) { if (!list !node) return; // sanity check!if (list->head == node) {list->head = node->next;} else {Node* prev = list->head;while (prev->next != node) prev = prev->next; // locate the node's previous nodeprev->next = node->next;}} Note that the remove function only removes the node from the list, it does not delete it. This allows us to restore the node to its original position, because the node itself was never modified (and thus still refers to its next node in the list). So long as we restore all removed nodes in the reverse order they were removed, we can easily restore the list. In order to delete a node completely, we simply remove it and then free it:void delete (List* list, Node* node) {if (!list !node) return; // sanity check!remove (list, node);free (node);} For a doubly-linked list, either two or four pointers must be changed. If the node about to be deleted is the head node, then the head node pointer must be changed to n->next and n->next->prev must be changed to NULL, otherwise, n->prev->next becomes n->next. In addition, if the node about to be deleted is the tail node, then the tail node pointer must be changed to n->prev and n->prev->next must be changed to NULL, otherwise, n->next->prev becomes n->prev. Deletion from a doubly-linked list is generally quicker than deletion from a singly linked list because a node in a doubly-linked list knows both its previous node and its next node, so there's no need to traverse the list to locate the previous node to the one being deleted. void remove (List* list, Node* node) {if (!list !node) return; // sanity check!if (list->head == node) {list->head = node->next;node->next->prev = NULL;} else {node->prev->next = node->next; }if (list->tail == node) {list->tail = node->prev;node->prev->next = NULL;} else {node->next->prev = node->prev; }} Again, to physically delete the node we simply remove and then free the node:void delete (List* list, Node* node) {if (!list !node) return; // sanity check!remove (list, node); free (node); }
What is a sentinel in programming?
A real-world sentinel is a soldier or guard, someone who keeps watch. In programming, a sentinel is typically a "dummy" node that is used specifically to mark the beginning or end of a data sequence. If we consider a singly-linked list (also known as a forward list), each node points forwards to the next node in the sequence. When we insert a new node into a list, we typically specify the node that will come immediately before it in the sequence because that node also points to the node that will (ultimately) come after it. Thus our algorithm can be encoded as follows: void insert_after (Node* node, Node* prev) { assert (node); assert (prev); node->next = prev->next; prev->next = node; } This is fine until we try and insert a new node at the start of the sequence or try to insert into an empty list. In both cases, p will be a null pointer because there can be no node that can come before the new node, n. Thus the assertion that p is non-null will fail. To cater for this, we must over-complicate the algorithm by testing for each of these special cases and, in order to do so, pass another argument to the function, namely the list itself: void insert_after (List* list, Node* node, Node* prev) { assert (list); assert (node); if (!list->head) { /* cater for empty list */ assert (!prev); list->head = node; node->next = null; } else if (!prev) { /* insert at head of list */ node->next = list->head; list->head = node; } else { node->next = prev->next; prev->next = node; } } However, if we place a sentinel at the beginning of the list, we guarantee that even an empty list will always have at least one node (the sentinel) and that whenever we insert a new node into the list there will always be a node that can come before that new node. Thus our original function works efficiently without having to deal with any special cases. The sentinel node is similar to any other node except that it does not store any data, it simply points to the first node in the sequence or to null if the list is empty.
How do you point to the first node in a linked list?
The list itself should maintain a pointer to the first node in the list. If it is NULL, the list is empty.
Program for inserting a new node in between two list in c?
To insert a new node between two lists, append the new node to the first list, then insert the head node of the second list after the new node.
Explain any two advantages using Single linked list over Doubly linked list and vice-versa?
Advantages of single linked list: # Decrease in storage space per linked list node # Simpler implementation Advantages of double linked list # Decrease in work when accessing a random node # Decrease in work when inserting or deleting a node
How do you write a algorithm of inserting an element at end of a linked list?
Algorithm to insert an element at the end of a linked listSpecial case: the list is empty.Create a new node for the element, assigning nullptr (0) to its next node.Assign the new node to the head of the list.Return a pointer to the new node and exit.All other cases: the list is not empty.Start at the head node (make it current).Repeat: while the current node has a next node, traverse to that node (make it current).Create a new node for the element, assigning nullptr (0) to its next node.Assign the new node as the current node's next node.Return a pointer to the new node and exit.
what are the various operations in linked list which can be performed on linked list?
Some common operations that can be performed on a linked list include inserting a node, deleting a node, searching for a specific node, traversing the list, and updating a node's value. Other operations may include reversing the list, merging two lists, sorting the list, and finding the length of the list.
How many pointers will have to be changed if a node is deleted from a linear linked list?
For a singly-linked list, only one pointer must be changed. If the node about to be deleted (let's call it node for the sake of argument) is the head of the list, then the head node pointer must be changed to node->next. Otherwise, the node that comes before the deleted node must change its next pointer to node->next. Note that given a singly-linked node has no knowledge of its previous node, we must traverse the list from the head in order to locate that particular node, unless the node is the head of the list: void remove (List* list, Node* node) { if (!list !node) return; // sanity check!if (list->head == node) {list->head = node->next;} else {Node* prev = list->head;while (prev->next != node) prev = prev->next; // locate the node's previous nodeprev->next = node->next;}} Note that the remove function only removes the node from the list, it does not delete it. This allows us to restore the node to its original position, because the node itself was never modified (and thus still refers to its next node in the list). So long as we restore all removed nodes in the reverse order they were removed, we can easily restore the list. In order to delete a node completely, we simply remove it and then free it:void delete (List* list, Node* node) {if (!list !node) return; // sanity check!remove (list, node);free (node);} For a doubly-linked list, either two or four pointers must be changed. If the node about to be deleted is the head node, then the head node pointer must be changed to n->next and n->next->prev must be changed to NULL, otherwise, n->prev->next becomes n->next. In addition, if the node about to be deleted is the tail node, then the tail node pointer must be changed to n->prev and n->prev->next must be changed to NULL, otherwise, n->next->prev becomes n->prev. Deletion from a doubly-linked list is generally quicker than deletion from a singly linked list because a node in a doubly-linked list knows both its previous node and its next node, so there's no need to traverse the list to locate the previous node to the one being deleted. void remove (List* list, Node* node) {if (!list !node) return; // sanity check!if (list->head == node) {list->head = node->next;node->next->prev = NULL;} else {node->prev->next = node->next; }if (list->tail == node) {list->tail = node->prev;node->prev->next = NULL;} else {node->next->prev = node->prev; }} Again, to physically delete the node we simply remove and then free the node:void delete (List* list, Node* node) {if (!list !node) return; // sanity check!remove (list, node); free (node); }
How to write an actual algorithm for inserting an element in a linked list?
Insert newNode into a linked list after targetNode Node currentNode = root while currentNode != targetNode currentNode = currentNode.next newNode.next = currentNode.next currentNode.next = newNode
Can we use doubly linked list as a circular linked list?
Yes. The tail node's next node is the head node, while the head node's previous node is the tail node.
What is a sentinel in programming?
A real-world sentinel is a soldier or guard, someone who keeps watch. In programming, a sentinel is typically a "dummy" node that is used specifically to mark the beginning or end of a data sequence. If we consider a singly-linked list (also known as a forward list), each node points forwards to the next node in the sequence. When we insert a new node into a list, we typically specify the node that will come immediately before it in the sequence because that node also points to the node that will (ultimately) come after it. Thus our algorithm can be encoded as follows: void insert_after (Node* node, Node* prev) { assert (node); assert (prev); node->next = prev->next; prev->next = node; } This is fine until we try and insert a new node at the start of the sequence or try to insert into an empty list. In both cases, p will be a null pointer because there can be no node that can come before the new node, n. Thus the assertion that p is non-null will fail. To cater for this, we must over-complicate the algorithm by testing for each of these special cases and, in order to do so, pass another argument to the function, namely the list itself: void insert_after (List* list, Node* node, Node* prev) { assert (list); assert (node); if (!list->head) { /* cater for empty list */ assert (!prev); list->head = node; node->next = null; } else if (!prev) { /* insert at head of list */ node->next = list->head; list->head = node; } else { node->next = prev->next; prev->next = node; } } However, if we place a sentinel at the beginning of the list, we guarantee that even an empty list will always have at least one node (the sentinel) and that whenever we insert a new node into the list there will always be a node that can come before that new node. Thus our original function works efficiently without having to deal with any special cases. The sentinel node is similar to any other node except that it does not store any data, it simply points to the first node in the sequence or to null if the list is empty.
How do you point to the first node in a linked list?
The list itself should maintain a pointer to the first node in the list. If it is NULL, the list is empty.
How do you implement stack using linked list in turbo c?
Assume the Linked list has following operations 1.node* insert(node* node, bool head); /* head = true if insertion at head else insertion at tail */ 2. node* remove(bool head); /* head = true if removal at head else removal at tail */ Now implement the stack functions as below. STK_RET push(node* pnode) { node* head; head = insert(pnode, true); /* insert the node at head */ if (head) return STK_OK; else return STK_NOK; } similarly pop can be implemented to remove the node at head Also the conventioin of inserting and removal from the tail can be used.
How to Print data of all nodes of linked list?
for (node=head; node!=null; node=node->next) printnode(node);
What operation is supported in constant time by the doubly linked list but not by the singly linked list?
examples:- delete this node (identified by a pointer)- insert a new node before this node- replace this node with another node
