diff --git a/data_structures/linked_list/doubly_linked_list_(circular)2.c b/data_structures/linked_list/doubly_linked_list_(circular)2.c
new file mode 100644
index 0000000000..b5970a5de7
--- /dev/null
+++ b/data_structures/linked_list/doubly_linked_list_(circular)2.c
@@ -0,0 +1,468 @@
+/* A menu driven program to create a doubly circular linked list, insert and delete nodes*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct node
+{
+    int data;
+    struct node * next;
+    struct node * prev;
+};
+
+struct node* new_node()
+{
+    int n;
+    struct node *temp=(struct node*)malloc(sizeof(struct node));
+    printf("Enter data: ");
+    scanf("%d", &n);
+    temp->data= n;
+    temp->prev=NULL;
+    temp->next=NULL;
+    return temp;
+}
+
+struct node* list_by_user(struct node* head)
+{
+    struct node *temp, *change=head;
+    int n;
+    do
+    {
+        temp=new_node();
+        if(head==NULL)
+        {
+            temp->next=temp;
+            temp->prev=temp;
+            head=temp;
+            change=temp;
+        }
+        else
+        {
+            temp->next=head;
+            head->prev=temp;
+            change->next=temp;
+            temp->prev=change;
+            change=temp;
+        }
+        printf("Enter 1 to continue, 0 to exit\n");
+        scanf("%d", &n);
+    }while(n);
+    return head;
+}
+
+struct node* list_n_nodes(struct node* head)
+{
+    int i, n;
+    struct node*temp, *change=head;
+    printf("Enter number of nodes: ");
+    scanf("%d",&n);
+    for(i=0; i<n; i++)
+    {
+        temp=new_node();
+        if(head==NULL)
+        {
+            temp->next=temp;
+            temp->prev=temp;
+            head=temp;
+            change=temp;
+        }
+        else
+        {
+            temp->next=head;
+            head->prev=temp;
+            change->next=temp;
+            temp->prev=change;
+            change=temp;
+        }
+    }
+    return head;
+}
+
+struct node* ins_at_beg(struct node* head)
+{
+    struct node* temp;
+    temp=new_node();
+    if(head==NULL)
+    {
+        temp->next=temp;
+        temp->prev=temp;
+        head=temp;
+    }
+    else{
+        temp->next=head;
+        head->prev->next=temp;
+        temp->prev=head->prev;
+        head->prev=temp;
+        head=temp;
+    }
+    return head;
+}
+
+struct node* ins_at_end(struct node* head)
+{
+    struct node* temp;
+    temp=new_node();
+    if(head==NULL)
+    {
+        temp->next=temp;
+        temp->prev=temp;
+        head=temp;
+    }
+    else{
+        temp->next=head;
+        head->prev->next=temp;
+        temp->prev=head->prev;
+        head->prev=temp;
+    }
+    return head;
+}
+
+struct node * ins_at_n_pos(struct node * head)
+{
+    int i, n;
+    struct node *temp, *change=head;
+    printf("Enter position: ");
+    scanf("%d",&n);
+    if(n==1)
+    {
+        head=ins_at_beg(head);
+        return head;
+    }
+    change=change->next;
+    for(i=1; i<n-2; i++)
+    {
+        change=change->next;
+    }
+    if(change->next==head)
+    {
+        head=ins_at_end(head);
+    }
+    else{
+        temp=new_node();
+        temp->next=change->next;
+        change->next->prev=temp;
+        change->next=temp;
+        temp->prev=change;
+    }
+    return head;
+
+}
+
+struct node * ins_before_n_val(struct node *head)
+{
+    int n,i;
+    struct node* temp, *change=head;
+    printf("Enter value: ");
+    scanf("%d",&n);
+    if(head==NULL)
+    {
+        printf("List doesn't exist\n");
+        return head;
+    }
+    if(head->data==n)
+    {
+        head=ins_at_beg(head);
+    }
+    else
+    {
+        while(change->next!=head && change->next->data!=n)
+        {
+            change=change->next;
+        }
+        if(change->next==head)
+        {
+            printf("Value not found.\n");
+        }
+        else
+        {
+            temp=new_node();
+            temp->next=change->next;
+            change->next->prev=temp;
+            change->next=temp;
+            temp->prev=change;
+        }
+    }
+    return head;
+}
+
+struct node * ins_after_n_val(struct node *head)
+{
+    int n,i;
+    struct node* temp, *change=head;
+    printf("Enter value: ");
+    scanf("%d",&n);
+    if(head==NULL)
+    {
+        printf("List doesn't exist\n");
+        return head;
+    }
+    if(head->data==n)
+    {
+        temp=new_node();
+        temp->next=change->next;
+        change->next->prev=temp;
+        change->next=temp;
+        temp->prev=change;
+    }
+    else
+    {
+        change=change->next;
+        while(change!=head && change->data!=n)
+        {
+            change=change->next;
+        }
+        if(change==head)
+        {
+            printf("Value not found.\n");
+        }
+        else
+        {
+            temp=new_node();
+            temp->next=change->next;
+            change->next->prev=temp;
+            change->next=temp;
+            temp->prev=change;
+        }
+    }
+    return head;
+}
+
+struct node* del_1st_node(struct node*head)
+{
+    struct node* temp, *change;
+    if(head==NULL)
+    {
+        printf("Create a list first.\n");
+        return head;
+    }
+    temp=head;
+    change=head->prev;
+    change->next=head->next;
+    head->next->prev=change;
+    head=head->next;
+    free(temp);
+    return head;
+}
+
+struct node* del_at_end(struct node* head)
+{
+    struct node* temp, *change;
+    if(head==NULL)
+    {
+        printf("Create a list first.\n");
+        return head;
+    }
+    temp=head->prev;
+    change=head->prev->prev;
+    change->next=head;
+    head->prev=change;
+    free(temp);
+    return head;
+}
+
+struct node* delete_n_val(struct node* head)
+{
+    struct node* temp, *change=head;
+    int n;
+    printf("Enter the val: ");
+    scanf("%d",&n);
+    if(head==NULL)
+    {
+        printf("Create a list first.\n");
+        return head;
+    }
+    if(head->data==n)
+    {
+        head=del_1st_node(head);
+    }
+    else
+    {
+        change=change->next;
+        while(change!=head && change->data!=n)
+        {
+            change=change->next;
+        }
+        if(change==head)
+        {
+            printf("Value doesn't exist\n");
+        }
+        else
+        {
+            temp=change;
+            change->prev->next=change->next;
+            change->next->prev=change->prev;
+            free(temp);
+        }
+    }
+    return head;
+}
+
+struct node* delete_after_n_val(struct node* head)
+{
+    struct node* temp, *change=head;
+    int n;
+    printf("Enter the val: ");
+    scanf("%d",&n);
+    if(head==NULL)
+    {
+        printf("Create a list first.\n");
+        return head;
+    }
+    if(head->data==n)
+    {
+        temp=head->next;
+        head->next->next->prev=head;
+        head->next=head->next->next;
+        free(temp);
+    }
+    else
+    {
+        change=change->next;
+        while(change!=head && change->data!=n)
+        {
+            change=change->next;
+        }
+        if(change==head)
+        {
+            printf("Value doesn't exist\n");
+        }
+        else if(change->next==head)
+        {
+            printf("No node exists after that.\n");
+        }
+        else
+        {
+            temp=change->next;
+            change->next->next->prev=change;
+            change->next=change->next->next;
+            free(temp);
+        }
+    }
+    return head;
+
+}
+
+struct node* delete_before_n_val(struct node* head)
+{
+    struct node* temp, *change=head;
+    int n;
+    printf("Enter the val: ");
+    scanf("%d",&n);
+    if(head==NULL)
+    {
+        printf("Create a list first.\n");
+        return head;
+    }
+    if(head->data==n)
+    {
+        printf("No node before this.\n");
+    }
+    else if(head->next->data==n)
+    {
+        head=del_1st_node(head);
+    }
+    else
+    {
+        change=change->next;
+        while(change!=head && change->data!=n)
+        {
+            change=change->next;
+        }
+        if(change==head)
+        {
+            printf("Value doesn't exist\n");
+        }
+        else
+        {
+            temp=change->prev;
+            temp->prev->next=change;
+            change->prev=temp->prev;
+            free(temp);
+        }
+    }
+    return head;
+}
+
+
+void print(struct node* head)
+{
+    struct node* change=head;
+    while(change->next!=head)
+    {
+        printf(" %x %d %x      ", change->prev,change->data,&change->data);
+        change=change->next;
+    }
+    printf(" %x %d %x      ", change->prev,change->data,&change->data);
+    printf("\n");
+}
+
+int main()
+{
+    struct node* head=NULL;
+    int option=0;
+    char choice;
+    printf(" Press:\n 1 a. To create a list of n nodes\n 1 b. To create a list of your choice.\n");
+    printf(" Press:\n 2 a. To insert a node at the begining\n 2 b. To insert a node at the end\n 2 c. To insert a node at the nth position.\n 2 d. To insert a node after the nth val.\n 2 e.To insert a node before the nth val.\n");
+    printf(" Press:\n 3 a. To delete a node at the begining\n 3 b. To delete a node at the end\n 3 c. To delete a node at the nth position.\n 3 d. To delete a node after the nth val.\n 3 e.To delete a node before the nth val.\n");
+    printf(" Press: 4 to see the list\n.");
+    do
+    {
+        printf("Enter option: ");
+        scanf("%d",&option);
+        switch(option)
+        {
+            case 1: printf("Enter choice: ");
+                    getchar();
+                    scanf("%c",&choice);
+                    switch(choice)
+                    {
+                        case 'a': head=list_n_nodes(head);
+                                  break;
+                        case 'b': head=list_by_user(head);
+                                  break;
+                    }
+                    break;
+            case 2: printf("Enter choice: ");
+                    getchar();
+                    scanf("%c",&choice);
+                    switch(choice)
+                    {
+                        case 'a': head= ins_at_beg(head);
+                                  break;
+                        case 'b': head= ins_at_end(head);
+                                  break;
+                        case 'c': head= ins_at_n_pos(head);
+                                  break;
+                        case 'd': head= ins_after_n_val(head);
+                                  break;
+                        case 'e': head= ins_before_n_val(head);
+                                  break;
+                    }
+                    break;
+            case 3: printf("Enter choice: ");
+                    getchar();
+                    scanf("%c",&choice);
+                    switch(choice)
+                    {
+                        case 'a': head=del_1st_node(head);
+                                  break;
+                        case 'b': head=del_at_end(head);
+                                  break;
+                        case 'c': head=delete_n_val(head);
+                                  break;
+                        case 'd': head=delete_after_n_val(head);
+                                  break;
+                        case 'e': head= delete_before_n_val(head);
+                                  break;
+                    }
+                    break;
+            case 4: print(head);
+                    break;
+        }
+
+        printf("Press 0 to exit, 1 to continue\n");
+        scanf("%d",&option);
+    }while(option);
+    return 0;
+}
+
diff --git a/data_structures/linked_list/polynomial_multiplication_using_linked_list.c b/data_structures/linked_list/polynomial_multiplication_using_linked_list.c
new file mode 100644
index 0000000000..a79f099cbc
--- /dev/null
+++ b/data_structures/linked_list/polynomial_multiplication_using_linked_list.c
@@ -0,0 +1,129 @@
+/* Multiplying two polynomials using linked list*/
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct node
+{
+    int data;
+    int exp;
+    struct node * next;
+};
+
+struct node * new_node()
+{
+    struct node* temp= (struct node*)malloc(sizeof(struct node));
+    printf("Enter coefficient: ");
+    scanf("%d",&temp->data);
+    printf("Enter exponent: ");
+    scanf("%d", &temp->exp);
+    temp->next=NULL;
+    return temp;
+}
+
+struct node* list(struct node* head)
+{
+    int i, n;
+    struct node *temp, *change=head;
+    printf("Enter number of nodes: ");
+    scanf("%d",&n);
+    for(i=0; i<n; i++)
+    {
+        temp=new_node();
+        if(head==NULL)
+        {
+            head=temp;
+            change=temp;
+        }
+        else
+        {
+            change->next=temp;
+            change=temp;
+        }
+    }
+    return head;
+}
+
+struct node * new_node_3()
+{
+    struct node* temp= (struct node*)malloc(sizeof(struct node));
+    temp->next=NULL;
+    return temp;
+}
+struct node* multiply(struct node* head1, struct node * head2, struct node* head3)
+{
+    struct node* temp, *change2, *change3,*del;
+    while(head1!=NULL)
+    {
+        change2=head2;
+        while(change2!=NULL)
+        {
+            temp=new_node_3();
+            temp->data=(head1->data)*(change2->data);
+            temp->exp=head1->exp+ change2->exp;
+            if(head3==NULL)
+           {
+               head3=temp;
+               change3=temp;
+           }
+           else
+            {
+                change3=head3;
+                while(change3->next!=NULL)
+                {
+                    if(change3->exp== temp->exp)
+                    {
+                        change3->data= change3->data + temp->data;
+                        break;
+                    }
+                    change3=change3->next;
+                }
+                if(change3->exp==temp->exp)
+                {
+                    change3->data= change3->data + temp->data;
+                }
+                else if(change3->next==NULL)
+                {
+                    change3->next=temp;
+                }
+            }
+          change2=change2->next;
+        }
+
+        del=head1;
+        head1=head1->next;
+        free(del);
+    }
+    return head3;
+}
+
+void print(struct node* head)
+{
+    struct node*change=head;
+    if(head==NULL)
+    {
+        printf("No list exists.\n");
+        return;
+    }
+    else{
+        while(change!=NULL)
+        {
+            printf("%d x ^(%d) + ",change->data, change->exp);
+            change=change->next;
+        }
+        printf("\n");
+    }
+}
+int main()
+{
+    struct node * head1=NULL, *head2=NULL;
+    head1=list(head1);
+    head2=list(head2);
+    struct node* head3=NULL;
+    head3=multiply(head1, head2, head3);
+    print(head3);
+    free(head1);
+    free(head2);
+    free(head3);
+    return 0;
+}