insert at the beginning of linked list

Author: Ankkkitt

Data Structures/Linked Lists/Singly Linked List/insert_at_beginning.cpp

@@ -0,0 +1,65 @@
+//  Problem Statement: 
+//
+//  Given an linked list and we have to add a node at the beginning of linked list. 
+//  The new node will be added at the beginning of a linked list.
+//
+//  Example: 
+//  Suppose we have an linked list : 50 -> 60
+//  Now insert(10)
+//  After insertion : 10 -> 50 -> 60
+
+// Solution: 
+// step 1. Create a new node for the value that has to be inserted and assign value to it.
+// step 2. now point the pointer of new node to the head of singly linked list. 
+// step 3: make the new node as our head. 
+
+// as we are doing constant operation 
+// Time complexity  --> O( 1 )
+// Space complexity --> O(1)
+
+#include <iostream>
+#include <bits/stdc++.h>
+using namespace std;
+
+class node{
+
+    public:
+    int data;
+    node *next;
+
+    node(int x){
+        data=x;
+        next=NULL;
+    }
+};
+
+node *insertBegin(node *head, int x)
+{
+    node *temp = new node(x);             // create a new node as temp for the value
+    temp->next=head;                      // making temp next as our head
+    return temp;                          // finally return
+}
+
+void display(node *head){
+
+    node *curr=head;
+    while(curr!=NULL)
+    {
+        cout<<curr->data<<" ";
+        curr=curr->next;
+    }
+}
+
+int main()
+{
+    node *head = new node(50);
+    head->next = new node(60);
+    cout<<"Linked list before inserting: ";
+    display(head);
+    cout<<endl;
+    head = insertBegin(head, 10);
+    cout<<"Linked list after inserting at the beginning: ";
+    display(head);
+
+
+}