Delete without head pointer

Problem Statement - link #

You are given a pointer/ reference to the node which is to be deleted from the linked list of N nodes. The task is to delete the node. Pointer/ reference to head node is not given. Note: No head reference is given to you. It is guaranteed that the node to be deleted is not a tail node in the linked list.

Your Task: You only need to complete the function deleteNode that takes reference to the node that needs to be deleted. The printing is done automatically by the driver code.

Expected Time Complexity: O(1)
Expected Auxiliary Space: O(1)

Examples #

Example 1:

Input:
N = 2
value[] = {1,2}
node = 1
Output: 2
Explanation: After deleting 1 from the
linked list, we have remaining nodes
as 2.

Example 2:

Input:
N = 4
value[] = {10,20,4,30}
node = 20
Output: 10 4 30
Explanation: After deleting 20 from
the linked list, we have remaining
nodes as 10, 4 and 30.

Constraints #

• 1 <= N <= 10^3

Solutions #

class Solution{
    public:
    /*
    struct Node {
    int data;
    struct Node *next;
    Node(int x) {
        data = x;
        next = NULL;
    }
    };
    */

    //Function to delete a node without any reference to head pointer.
    void deleteNode(Node *del)
    {
       // Your code here
       swap(del->data,del->next->data);
       Node* temp = del->next;
       del->next = del->next->next;
       delete temp;
    }
};