Stack Using Linked List

#include <stdio.h>

#include<stdlib.h>

#include<math.h>

#define size 5

int top=-1;

void push(void);

void pop(void);

void peek_top(void);

void isEmpty(void);

void isFull(void);

void display(void);

struct stack{

int data;

struct node *next;

};

struct stack *head=0;

void main() {

int c,e;

do{

switch(c)

{

case 1:

push();

break;

case 2:

pop();

break;

case 3:

peek_top();

break;

case 4:

isEmpty();

break;

case 5:

isFull();

break;

case 6:

display();

break;

case 7:

printf("\n----Exit from program successfully----");

printf("\n--------------Thank you--------------");

exit(0);

}

printf("\n1 : Push\n2 : Pop\n3 : Peek\n4 : isEmpty\n5 : isFull\n6 : Display\n7 : Exit");

printf("\nEnter your choice : ");

scanf("%d",&c);

}while(c);

}

void push()

{

struct stack *newnode,*temp;

if(top<size)

{

newnode=(struct stack *)malloc(sizeof(struct stack));

printf("\nEnter data : ");

scanf("%d",&newnode->data);

newnode->next=0;

top++;

if(head==0)

{

head=temp=newnode;

}

else

{

temp=head;

while(temp->next!=0)

{

temp=temp->next;

}

temp->next=newnode;

}

}

else

{

printf("\nStack is full");

}

}

void display()

{

struct stack *temp;

temp=head;

while(temp!=0)

{

printf("--%d",temp->data);

temp=temp->next;

}

}

void pop()

{

struct stack *temp,*prevnode;

printf("\n\n----Deletion From End----");

temp=head;

top--;

while(temp->next!=0)

{

prevnode=temp;

temp=temp->next;

}

if(temp==head)

{

head=0;

}

else

{

prevnode->next=0;

}

free(temp);

printf("\nTop : %d",top);

}

void peek_top()

{

struct stack *temp;

temp=head;

while(temp->next!=0)

{

temp=temp->next;

}

printf("\nTop : %d",top);

printf("\nPeek : %d",temp->data);

}

void isEmpty()

{

if(top==-1)

{

printf("\nStack is empty");

}

else

{

printf("\nStack is not empty");

}

}

void isFull()

{

if(top==size-1)

{

printf("\nStack is full");

}

else

{

printf("\nStack is not full");

}

}

Stack Using Array

#include <stdio.h>

#include<stdlib.h>

#include<math.h>

#define size 100

int stack[size];

int top=-1;

void push(void);

void pop(void);

void peek_top(void);

void isEmpty(void);

void isFull(void);

void display(void);

void main() {

int c,e;

do{

switch(c)

{

case 1:

push();

break;

case 2:

pop();

break;

case 3:

peek_top();

break;

case 4:

isEmpty();

break;

case 5:

isFull();

break;

case 6:

display();

break;

case 7:

printf("\n\n----Exit from program successfully----");

printf("\n--------------Thank you--------------");

exit(0);

}

printf("\n1 : Push\n2 : Pop\n3 : Peek\n4 : isEmpty\n5 : isFull\n6 : Display");

printf("\nEnter your choice : ");

scanf("%d",&c);

}while(c);

}

void push()

{

int v;

printf("\nEnter value : ");

scanf("%d",&v);

if(top==size-1)

{

printf("\nStack is full!!");

}

else

{

top++;

stack[top]=v;

}

}

void display()

{

int i;

if(top==-1)

{

printf("\nStack is empty");

}

else

{

for(i=0;i<=top;i++)

{

printf("--%d",stack[i]);

}

}

}

void pop()

{

if(top==-1)

{

printf("\nStack is empty!!");

}

else

{

top--;

}

}

void peek_top()

{

printf("\nTop : %d",top);

printf("\nTop Value: %d",stack[top]);

}

void isEmpty()

{

if(top==-1)

{

printf("\nStack is empty!!");

}

else

{

printf("\nStack is not empty!!");

}

}

void isFull()

{

if(top==size-1)

{

printf("\nStack is full!!");

}

else

{

printf("\nStack is not full!!");

}

}

Doubly Circular Linked List

A doubly circular linked list is a type of linked list where each node has both a "next" and a "previous" pointer, allowing for traversal in both directions. Additionally, the last node in the list points back to the first node, forming a circle.

#include <stdio.h>

#include <stdlib.h>

struct Node {

int data;

struct Node* next;

struct Node* prev;

};

struct DoublyCircularLinkedList {

struct Node* head;

int count;

};

struct Node* create_node(int data) {

struct Node* node = (struct Node*)malloc(sizeof(struct Node));

node->data = data;

node->next = NULL;

node->prev = NULL;

return node;

}

struct DoublyCircularLinkedList* create_list() {

struct DoublyCircularLinkedList* list = (struct DoublyCircularLinkedList*)malloc(sizeof(struct DoublyCircularLinkedList));

list->head = NULL;

list->count = 0;

return list;

}

void append(struct DoublyCircularLinkedList* list, int data) {

struct Node* node = create_node(data);

if (list->head == NULL) {

list->head = node;

node->next = node; // make the node point to itself

node->prev = node;

} else {

node->next = list->head;

node->prev = list->head->prev;

list->head->prev->next = node;

list->head->prev = node;

}

list->count++;

}

int remove_node(struct DoublyCircularLinkedList* list, int data) {

if (list->head == NULL) {

return 0;

}

struct Node* current = list->head;

do {

if (current->data == data) {

if (current == list->head) {

list->head = current->next;

}

current->prev->next = current->next;

current->next->prev = current->prev;

free(current);

list->count--;

return 1;

}

current = current->next;

} while (current != list->head);

return 0;

}

void print_list(struct DoublyCircularLinkedList* list) {

if (list->head == NULL) {

return;

}

struct Node* current = list->head;

do {

printf("%d ", current->data);

current = current->next;

} while (current != list->head);

printf("\n");

}

int main() {

struct DoublyCircularLinkedList* list = create_list();

append(list, 1);

append(list, 2);

append(list, 3);

print_list(list); // output: 1 2 3

remove_node(list, 2);

print_list(list); // output: 1 3

return 0;

}