diff --git a/DS/C/Lab/Week9/CircularPolyAdd.c b/DS/C/Lab/Week9/CircularPolyAdd.c
new file mode 100644
index 0000000..452d2d4
--- /dev/null
+++ b/DS/C/Lab/Week9/CircularPolyAdd.c
@@ -0,0 +1,123 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct Node {
+    int coefficient;
+    int exponent;
+    struct Node *next;
+    struct Node *prev;
+} Node;
+
+Node *createNode(int coefficient, int exponent) {
+    Node *newNode = (Node *)malloc(sizeof(Node));
+    if (newNode == NULL) {
+        printf("Memory allocation failed.\n");
+        exit(1);
+    }
+    newNode->coefficient =coefficient;
+    newNode->exponent = exponent;
+    newNode->next = NULL;
+    newNode->prev = NULL;
+    return newNode;
+}
+
+void insertEnd(Node **head, int coefficient, int exponent) {
+    Node *newNode = createNode(coefficient, exponent);
+    if (*head == NULL) {
+        *head = newNode;
+        (*head)->next = *head;
+        (*head)->prev = *head;
+    } else {
+        Node *last = (*head)->prev;
+        newNode->next = *head;
+        newNode->prev = last;
+        last->next = newNode;
+        (*head)->prev = newNode;
+    }
+}
+
+Node *addPolynomials(Node *poly1, Node *poly2) {
+    if (poly1 == NULL) return poly2;
+    if (poly2 == NULL) return poly1;
+
+    Node *result = NULL;
+    Node *temp1 = poly1, *temp2 = poly2;
+
+    do {
+        if (temp1->exponent > temp2->exponent) {
+            insertEnd(&result, temp1->coefficient, temp1->exponent);
+            temp1 = temp1->next;
+        } else if (temp1->exponent < temp2->exponent) {
+            insertEnd(&result, temp2->coefficient, temp2->exponent);
+            temp2 = temp2->next;
+        } else {
+            int sum = temp1->coefficient + temp2->coefficient;
+            if (sum != 0) {
+                insertEnd(&result, sum, temp1->exponent);
+            }
+            temp1 = temp1->next;
+            temp2 = temp2->next;
+        }
+    } while (temp1 != poly1 || temp2 != poly2);
+
+    return result;
+}
+
+void displayPolynomial(Node *head) {
+    if (head == NULL) {
+        printf("Empty polynomial.\n");
+        return;
+    }
+
+    Node *temp = head;
+    do {
+        printf("(%dx^%d) ", temp->coefficient, temp->exponent);
+        temp = temp->next;
+        if (temp != head) {
+            printf("+ ");
+        }
+    } while (temp != head);
+    printf("\n");
+}
+
+void insert(Node** poly, int coef, int exp) {
+ Node* temp = (Node*) malloc(sizeof(Node));
+ temp->coefficient = coef;
+ temp->exponent = exp;
+ temp->next = NULL;
+
+ if (*poly == NULL) { *poly = temp; return; }
+
+ Node* current = *poly;
+
+ while (current->next != NULL) current = current->next;
+
+ current->next = temp;
+}
+
+int main() {
+    Node *poly1 = NULL, *poly2 = NULL;
+
+    insertEnd(&poly1, 5, 3);  // 5x^3
+    insertEnd(&poly1, 4, 1);  // 4x^1
+    insertEnd(&poly1, 3, 0);  // 3x^0
+
+    insertEnd(&poly2, 3, 2);  // 3x^2
+    insertEnd(&poly2, 2, 1);  // 2x^1
+    insertEnd(&poly2, 1, 0);  // 1x^0
+
+    printf("First polynomial: ");
+    displayPolynomial(poly1);
+
+    printf("Second polynomial: ");
+    displayPolynomial(poly2);
+
+    Node *sum = addPolynomials(poly1, poly2);
+
+    printf("Sum of the polynomials: ");
+    displayPolynomial(sum);
+
+
+
+    return 0;
+}
diff --git a/DS/C/Lab/Week9/Doubly_Circular_LL.c b/DS/C/Lab/Week9/Doubly_Circular_LL.c
new file mode 100644
index 0000000..4a403d4
--- /dev/null
+++ b/DS/C/Lab/Week9/Doubly_Circular_LL.c
@@ -0,0 +1,115 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct cnode *cnptr;
+typedef struct cnode
+{
+    int data;
+    cnptr next;
+    cnptr prev;
+}cnode;
+cnptr last=NULL;
+
+cnptr createCnode(int val)
+{
+    cnptr temp=(cnptr)malloc(sizeof(cnode));
+    temp->data=val;
+    temp->next=NULL;
+    temp->prev=NULL;
+    return temp;
+}
+void insertBegin(int val)
+{
+    cnptr temp=createCnode(val);
+    if(last==NULL)
+    {
+        last=temp;
+        last->next=last;
+        last->prev=last;
+    }
+    else
+    {
+        temp->next=last->next;//head
+        last->next->prev=temp;
+        temp->prev=last;
+        last->next=temp;
+    }
+}
+void deleteend()
+{
+    cnptr current;
+    if(last==NULL)
+    {
+        printf("List is empty");
+    }
+    else
+    {
+        cnptr previous=last->prev;
+        previous->next=last->next;
+        last->next->prev=previous;
+        free(last);
+        last=previous;
+    }
+}
+void revtraverse()
+{
+    cnptr current=last;
+    printf("%d ",current->data);
+    current=current->prev;
+    while(current!=last)
+    {
+        printf("%d ",current->data);
+        current=current->prev;
+    }
+    printf("\n");
+}
+void traverse()
+{
+    cnptr current=last;
+    current=current->next;
+    while(current!=last)
+    {
+        printf("%d ",current->data);
+        current=current->next;
+    }
+    printf("%d\n",current->data);
+}
+int main()
+{
+    char contin='y';
+    int choice;
+    while(contin=='y')
+    {
+        printf("What do you want to do? \n 1. For inserting at beginning \n 2. For deleting at the end. \n 3. For traversing the doubly LL\n");
+        scanf("%d",&choice);
+        switch(choice)
+        {
+        case 1:
+            {
+                int val;
+                printf("Enter the value\n");
+                scanf("%d",&val);
+                insertBegin(val);
+                break;
+            }
+        case 2:
+            {
+                deleteend();
+                printf("Element deleted\n");
+                break;
+            }
+        case 3:
+            {
+                printf("elements of the list are\n");
+                traverse();
+                break;
+            }
+        }
+        printf("continue?(y/n)\n");
+        fflush(stdin);
+        scanf("%c",&contin);
+    }
+
+}
+
+
diff --git a/DS/C/Lab/Week9/MultiPoly.c b/DS/C/Lab/Week9/MultiPoly.c
new file mode 100644
index 0000000..541ce72
--- /dev/null
+++ b/DS/C/Lab/Week9/MultiPoly.c
@@ -0,0 +1,121 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+// Structure to represent a term in a polynomial
+typedef struct Node {
+    int coeff;
+    int power;
+    struct Node* next;
+    struct Node* prev;
+} Node;
+
+Node* createNode(int coeff, int power) {
+    Node* newNode = (Node*)malloc(sizeof(Node));
+    newNode->coeff = coeff;
+    newNode->power = power;
+    newNode->next = NULL;
+    newNode->prev = NULL;
+    return newNode;
+}
+
+Node* insertTerm(Node* head, int coeff, int power) {
+    Node* temp = createNode(coeff, power);
+    if (head == NULL) {
+        head = temp;
+        head->next = head;
+        head->prev = head;
+    } else {
+        Node* last = head->prev;
+        temp->next = head;
+        temp->prev = last;
+        last->next = temp;
+        head->prev = temp;
+    }
+    return head;
+}
+
+void displayPolynomial(Node* head) {
+    if (head == NULL) {
+        printf("Polynomial is empty\n");
+        return;
+    }
+
+    Node* temp = head;
+    do {
+        printf("%dx^%d ", temp->coeff, temp->power);
+        temp = temp->next;
+        if (temp != head) {
+            printf("+ ");
+        }
+    } while (temp != head);
+    printf("\n");
+}
+
+Node* multiplyPolynomials(Node* poly1, Node* poly2) {
+    if (poly1 == NULL || poly2 == NULL) {
+        printf("One of the polynomials is empty\n");
+        return NULL;
+    }
+
+    Node* result = NULL;
+    Node* temp1 = poly1;
+
+    do {
+        Node* temp2 = poly2;
+        do {
+            int coeff = temp1->coeff * temp2->coeff;
+            int power = temp1->power + temp2->power;
+            result = insertTerm(result, coeff, power);
+            temp2 = temp2->next;
+        } while (temp2 != poly2);
+        temp1 = temp1->next;
+    } while (temp1 != poly1);
+
+    Node* current = result;
+    do {
+        Node* next = current->next;
+        while (next != result) {
+            if (current->power == next->power) {
+                current->coeff += next->coeff;
+                Node* temp = next;
+                next->prev->next = next->next;
+                next->next->prev = next->prev;
+                next = next->next;
+                free(temp);
+            } else {
+                next = next->next;
+            }
+        }
+        current = current->next;
+    } while (current != result);
+
+    return result;
+}
+
+
+int main() {
+    Node* poly1 = NULL;
+    Node* poly2 = NULL;
+    Node* result = NULL;
+
+    // Example: Polynomial 1: 5x^2 + 2x + 10, Polynomial 2: 2x^1 + 4
+    poly1 = insertTerm(poly1, 5, 2);
+    poly1 = insertTerm(poly1, 2, 1);
+    poly1 = insertTerm(poly1, 10, 0);
+
+    poly2 = insertTerm(poly2, 2, 1);
+    poly2 = insertTerm(poly2, 4, 0);
+
+    printf("Polynomial 1: ");
+    displayPolynomial(poly1);
+
+    printf("Polynomial 2: ");
+    displayPolynomial(poly2);
+
+    result = multiplyPolynomials(poly1, poly2);
+
+    printf("Result of Multiplication: ");
+    displayPolynomial(result);
+
+    return 0;
+}
diff --git a/DS/C/Lab/Week9/PolyAdder.c b/DS/C/Lab/Week9/PolyAdder.c
new file mode 100644
index 0000000..b68d748
--- /dev/null
+++ b/DS/C/Lab/Week9/PolyAdder.c
@@ -0,0 +1,165 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+typedef struct pnode* pptr;
+typedef struct pnode
+{
+    int coeff;
+    int expo;
+    pptr next;
+} pnode;
+
+// create node in the linked list
+pptr createNode(int coeff,int expo)
+{
+    pptr temp = (pptr)malloc(sizeof(pnode));
+    if (temp == NULL)
+    {
+        printf("Heap is full");
+        free(temp);
+        exit(0);
+    }
+    temp->coeff = coeff;
+    temp->expo = expo;
+    temp->next = NULL;
+    return temp;
+}
+
+//insert element at the end of the linked list
+void insertEnd(int coeff,int expo,pptr* head)
+{
+    pptr temp = createNode(coeff,expo);
+    if(*head == NULL)
+    {
+        *head = temp;
+    }
+    else
+    {
+        pptr current = *head;
+        while(current->next)
+        {
+            current = current->next;
+        }
+        current->next = temp;
+    }
+}
+
+
+void attach(int coeff,int expo,pptr* rear)//we do *rear as we pdate the rear and ,=move it forword otherwise we didi not need to change it if only rear ke aage add karna hota
+{
+    pptr temp;
+    temp = (pptr)malloc(sizeof(pnode));
+    temp->coeff = coeff;
+    temp->expo = expo;
+    temp->next = NULL;
+
+    (*rear)->next = temp;
+    *rear = temp;
+}
+
+pptr polyAdd(pptr A,pptr B)
+{
+    pptr C,rear,temp;
+    rear = (pptr)malloc(sizeof(pnode));
+    C = rear;
+    while(A && B)
+    {
+        int diff = A->expo - B->expo;
+
+        //A->expo < B->expo
+        if(diff<0)
+        {
+            attach(B->coeff,B->expo,&rear);
+            B = B->next;
+            break;
+        }
+
+        //A->expo > B->expo
+        else if(diff>0)
+        {
+            attach(A->coeff,A->expo,&rear);
+            A = A->next;
+            break;
+        }
+
+        //A->expo = B->expo
+        else
+        {
+            int sum = A->coeff + B->coeff;
+            if(sum)
+            {
+                attach(sum,A->expo,&rear);
+            }
+            A = A->next;
+            B = B->next;
+        }
+    }
+
+    //attach remaining nodes for A and B
+    for(;A;A = A->next)
+    {
+        attach(A->coeff,A->expo,&rear);
+    }
+    for(;B;B=B->next)
+    {
+        attach(B->coeff,B->expo,&rear);
+    }
+
+    temp = C;
+    C = C->next;
+    free(temp);
+    return C;
+}
+
+int main()
+{
+    pptr A, B;
+    A = B = NULL;
+
+    insertEnd(3, 3, &A);
+    insertEnd(4, 2, &A);
+    insertEnd(1, 0, &A);
+
+    pptr current = A;
+    printf("1st Polynomial is: ");
+    if (current) {
+        printf("%dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    while (current) {
+        printf(" + %dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    printf("\n");
+
+    insertEnd(6, 4, &B);
+    insertEnd(5, 2, &B);
+    insertEnd(4, 1, &B);
+
+    current = B;
+    printf("2nd Polynomial is: ");
+    if (current) {
+        printf("%dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    while (current) {
+        printf(" + %dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    printf("\n");
+
+    pptr C = polyAdd(A, B);
+    current = C;
+    printf("Added Polynomial is: ");
+    if (current) {
+        printf("%dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    while (current) {
+        printf(" + %dx^%d", current->coeff, current->expo);
+        current = current->next;
+    }
+    printf("\n");
+
+    return 0;
+}
diff --git a/DS/C/Lab/Week9/WashingMachine.c b/DS/C/Lab/Week9/WashingMachine.c
new file mode 100644
index 0000000..9d0aa8f
--- /dev/null
+++ b/DS/C/Lab/Week9/WashingMachine.c
@@ -0,0 +1,120 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+typedef struct cnode *cnptr;
+typedef struct cnode
+{
+    int data;
+    char name[100];
+    cnptr next;
+    cnptr prev;
+} cnode;
+
+cnptr last = NULL;
+
+cnptr createCnode(int val)
+{
+    cnptr temp = (cnptr)malloc(sizeof(cnode));
+    temp->data = val;
+    temp->next = NULL;
+    temp->prev = NULL;
+    return temp;
+}
+
+void insertBegin(int val, char nam[])
+{
+    cnptr temp = createCnode(val);
+    strcpy(temp->name, nam);
+    if (last == NULL)
+    {
+        last = temp;
+        last->next = last;
+        last->prev = last;
+    }
+    else
+    {
+        temp->next = last->next; // head
+        last->next->prev = temp;
+        temp->prev = last;
+        last->next = temp;
+    }
+}
+
+void deleteend()
+{
+    if (last == NULL)
+    {
+        printf("Queue is empty\n");
+    }
+    else
+    {
+        printf("Next person is %s for %d mins\n", last->name, last->data);
+        cnptr previous = last->prev;
+        previous->next = last->next;
+        last->next->prev = previous;
+        free(last);
+        last = previous;
+
+        if (last->next == last) // If the list becomes empty
+            last = NULL;
+    }
+}
+
+void traverse()
+{
+    if (last == NULL) {
+        printf("Queue is empty\n");
+        return;
+    }
+
+    cnptr current = last->next;
+    do {
+        printf("%s (%d mins) ", current->name, current->data); // Print name AND time
+        current = current->next;
+    } while (current != last->next);
+
+    printf("\n");
+}
+
+int main()
+{
+    char contin = 'y';
+    int choice;
+    while (contin == 'y')
+    {
+        printf("What do you want to do? \n 1. Add person to queue \n 2. Pass the chance to next person \n 3. View the Queue\n");
+        scanf("%d", &choice);
+        switch (choice)
+        {
+        case 1:
+            {
+                int val;
+                printf("Enter the name:\n");
+                fflush(stdin);
+                char name[100];
+                gets(name);
+                printf("Enter the time in minutes: \n");
+                scanf("%d", &val);
+                insertBegin(val, name);
+                break;
+            }
+        case 2:
+            {
+                deleteend();
+                break;
+            }
+        case 3:
+            {
+                printf("People in the Queue are\n");
+                traverse();
+                break;
+            }
+        }
+        printf("continue? (y/n)\n");
+        fflush(stdin);
+        scanf(" %c", &contin);
+    }
+
+    return 0;
+}