Delete a Node
Problem Statement :
Delete the node at a given position in a linked list and return a reference to the head node. The head is at position 0. The list may be empty after you delete the node. In that case, return a null value. Example: list=0->1->2->3 position=2 After removing the node at position 2, list'= 0->1->-3. Function Description: Complete the deleteNode function in the editor below. deleteNode has the following parameters: - SinglyLinkedListNode pointer llist: a reference to the head node in the list - int position: the position of the node to remove Returns - SinglyLinkedListNode pointer: a reference to the head of the modified list Input Format: The first line of input contains an integer n, the number of elements in the linked list. Each of the next n lines contains an integer, the node data values in order. The last line contains an integer, position, the position of the node to delete. Constraints: 1. 1<=n<=1000 2. 1<=list[i]<=1000
Solution :
Solution in C :
In C:
//the following function is all that is needed to complete
// the challenge in hackerrank platform.
SinglyLinkedListNode* deleteNode(SinglyLinkedListNode* llist, int position) {
if((position) == 0) {
return llist->next;
}
llist->next = deleteNode(llist->next, position-1);
return llist;
}
In C++:
//the following function is all that is needed to complete
//the challenge in hackerrank platform
Node* Delete(Node *head, int position)
{
// Complete this method
Node *prev = NULL;
Node *ptr = head;
int pos = 0;
if(position==0)
{
head=head->next;
delete (ptr);
}
else
{
while(position!=pos)
{
++pos;
prev=ptr;
ptr=ptr->next;
}
if(ptr!=NULL)
{
prev->next=ptr->next;
delete (ptr);
}
}
return head;
}
In Java:
//the following method is all that is needed to complete the
//challenge in hackerrank plartform
static SinglyLinkedListNode deleteNode(SinglyLinkedListNode llist, int position) {
int currentNodePosition = 0;
SinglyLinkedListNode head = llist;
SinglyLinkedListNode currentNode = llist;
if (position == 0) {
head = head.next;
return head;
}
while (currentNodePosition < position - 1) {
currentNode = currentNode.next;
currentNodePosition++;
}
if (currentNode.next != null && currentNode.next.next != null) {
currentNode.next = currentNode.next.next;
}
return head;
}
In Python 3:
#the following method is all that is needed to complete the
#challenge in hackerrank platfrom
def Delete(head, position):
currentPos = 0
prevNode = None
node = head
while currentPos < position:
currentPos = currentPos+1
prevNode = node
node = node.next
if prevNode is not None:
prevNode.next = node.next
return head
else:
n = node.next
node.next = None
return n
View More Similar Problems
Pair Sums
Given an array, we define its value to be the value obtained by following these instructions: Write down all pairs of numbers from this array. Compute the product of each pair. Find the sum of all the products. For example, for a given array, for a given array [7,2 ,-1 ,2 ] Note that ( 7 , 2 ) is listed twice, one for each occurrence of 2. Given an array of integers, find the largest v
View Solution →Lazy White Falcon
White Falcon just solved the data structure problem below using heavy-light decomposition. Can you help her find a new solution that doesn't require implementing any fancy techniques? There are 2 types of query operations that can be performed on a tree: 1 u x: Assign x as the value of node u. 2 u v: Print the sum of the node values in the unique path from node u to node v. Given a tree wi
View Solution →Ticket to Ride
Simon received the board game Ticket to Ride as a birthday present. After playing it with his friends, he decides to come up with a strategy for the game. There are n cities on the map and n - 1 road plans. Each road plan consists of the following: Two cities which can be directly connected by a road. The length of the proposed road. The entire road plan is designed in such a way that if o
View Solution →Heavy Light White Falcon
Our lazy white falcon finally decided to learn heavy-light decomposition. Her teacher gave an assignment for her to practice this new technique. Please help her by solving this problem. You are given a tree with N nodes and each node's value is initially 0. The problem asks you to operate the following two types of queries: "1 u x" assign x to the value of the node . "2 u v" print the maxim
View Solution →Number Game on a Tree
Andy and Lily love playing games with numbers and trees. Today they have a tree consisting of n nodes and n -1 edges. Each edge i has an integer weight, wi. Before the game starts, Andy chooses an unordered pair of distinct nodes, ( u , v ), and uses all the edge weights present on the unique path from node u to node v to construct a list of numbers. For example, in the diagram below, Andy
View Solution →Heavy Light 2 White Falcon
White Falcon was amazed by what she can do with heavy-light decomposition on trees. As a resut, she wants to improve her expertise on heavy-light decomposition. Her teacher gave her an another assignment which requires path updates. As always, White Falcon needs your help with the assignment. You are given a tree with N nodes and each node's value Vi is initially 0. Let's denote the path fr
View Solution →