Create mergeLL.cpp

mergeLL.cpp

@@ -0,0 +1,112 @@
+#include<iostream>
+using namespace std;
+#include "created_linked_list.cpp"
+
+Node * insertion(){
+    Node * head=NULL;
+    Node * tail=NULL;
+    int a;
+    cin>>a;
+    while(a!=-1){
+        Node *newnode= new Node(a);
+        if(head==NULL){
+            head=newnode;
+            tail=head;
+        }
+        else{
+            tail->next=newnode;
+            tail=tail->next;
+        }
+        cin>>a;
+    }
+    return head;
+}
+
+void display(Node * head){
+    while(head!=NULL){
+        cout<<head->data<<endl;
+        head=head->next;
+    }
+}
+
+Node * mid(Node * head){
+    Node * slow = head;
+    Node * fast = head->next;
+    while(fast!=NULL ||fast->next!=NULL){
+        slow=slow->next;
+        fast=fast->next->next;
+    }
+    return slow;
+}
+
+Node * merge_two_sorted_LL(Node *head1,Node * head2){
+    Node * real =NULL;
+    Node * final_tail=NULL;
+    if(head1->data<head2->data){
+        real=head1;
+        head1=head1->next;
+        final_tail=real;
+    }
+    else{
+        real=head2;
+        head2=head2->next;
+        final_tail=real;
+
+    }
+    while(head1!= NULL&& head2!=NULL){
+        if(head1->data<head2->data){
+            final_tail->next=head1;
+            final_tail=final_tail->next;
+            head1=head1->next;
+        }
+        else{
+            final_tail->next=head2;
+            final_tail=final_tail->next;
+            head2=head2->next;
+        }
+    }
+
+    if(head1!=NULL){
+        final_tail->next=head1;
+    }
+    else{
+        final_tail->next=head2;
+    }
+    return real;
+}
+
+Node * merge(Node * head){
+    if(head->next==NULL||head==NULL){
+        return head;
+    }
+
+    Node * mmiddle=mid(head);
+    Node * second=mmiddle->next;
+    mmiddle->next=NULL;
+    Node * first=head;
+
+    Node * h1=merge(first);
+    Node * h2=merge(second);
+
+    Node * ans=merge_two_sorted_LL(h1,h2);
+    return ans;
+
+}
+
+int main(){
+   /* Node * head=insertion();
+    cout<<"the linked list before the mergesort operation is:-"<<endl;
+    display(head);
+
+    head=merge(head);
+    cout<<"the linked list after performing the merge sort operation is:-"<<endl;
+
+    display(head);
+
+    */
+
+   Node * head1=insertion();
+   Node * h2=insertion();
+   Node * ans=merge_two_sorted_LL(head1,h2);
+   display(ans);
+}