15.Implement stack using linked list.

//Program to implement stack using linked list.
#include<stdio.h>
#include<conio.h>
#include<malloc.h>

struct node {
    int t_no;
    char p_name[50];
    struct node *link;
} *temp = NULL, *top = NULL;

void insert() {
    clrscr();
    temp = (struct node *) malloc(sizeof(struct node));
    printf("\n Enter ticket no. : ");
    scanf("%d", &temp->t_no);
    printf(" Enter passenger name: ");
    scanf("%s", &temp->p_name);
    temp->link = top;
    top = temp;
    printf("\n Insert Successful!");
    printf("\n Press any key to continue...");
    getch();
}
void display() {
    clrscr();
    if (top == NULL) {
        printf("\n The stack is empty!");
    } else {
        temp = top;
        while (temp != NULL) {
            printf("\n Ticket no. : %d", temp->t_no);
            printf("\n Passenger name: ");
            puts(temp->p_name);
            temp = temp->link;
        }
    }
    printf("\n Press any key to continue...");
    getch();
}
void delete_node() {
    clrscr();
    if (top == NULL) {
        printf("\n The stack is empty!");
    } else {
        temp = top;
        top = top->link;
        printf("\n Deleted the following record: ");
        printf("\n Ticket no. : %d", temp->t_no);
        printf("\n Passenger name: ");
        puts(temp->p_name);
        free(temp);
    }
    printf("\n Press any key to continue...");
    getch();
}
void main()
{
    int choice;
    clrscr();
    while(1) {
        clrscr();
        printf("\n\t\t\tMain Menu\n\t1.Insert\n\t2.Display\n\t3.Delete\n\t4.Exit");
        printf("\n Enter your choice: ");
        scanf("%d", &choice);
        switch(choice) {
            case 1:
                insert();
                break;

            case 2:
                display();
                break;

            case 3:
                delete_node();
                break;

            case 4:
                return;
        }
    }
}

//Program to implement queue using linked list.
#include<conio.h>
#include<stdio.h>
#include<malloc.h>

struct node {
    int t_no;
    char p_name[50];
    struct node *link;
} *temp=NULL, *front=NULL, *rear=NULL;

void insert() {
    clrscr();
    temp = (struct node *) malloc(sizeof(struct node));
    printf("\n Enter ticket no.: ");
    scanf("%d", &temp->t_no);
    printf("\n Enter passenger name: ");
    scanf("%s", &temp->p_name);
    temp->link = NULL;

    if (front == NULL) {
        front = temp;
        rear = temp;
    } else {
        rear->link = temp;
        rear = temp;
    }
    printf("\n Insert Successful!");
    printf("\n Press any key to continue...");
    getch();
}
void display() {
    clrscr();
    if (front == NULL) {
        printf("\n The queue is empty!");
    } else {
        temp = front;
        while (temp != NULL) {
            printf("\n Ticket no. : %d", temp->t_no);
            printf("\n Passenger name: ");
            puts(temp->p_name);
            temp = temp->link;
        }
    }
    printf("\n Press any key to continue...");
    getch();
}
void delete_node() {
    clrscr();
    if (front == NULL) {
        printf("\n The queue is empty!");
    } else {
        temp = front;
        front = front->link;
        printf("\n Deleted the following record: ");
        printf("\n Ticket no. : %d", temp->t_no);
        printf("\n Passenger name: ");
        puts(temp->p_name);
        free(temp);
    }
    printf("\n Press any key to continue...");
    getch();
}
void main()
{
    int choice;
    clrscr();
    while(1) {
        clrscr();
        printf("\n\t\t\tMain Menu\n\t1.Insert\n\t2.Display\n\t3.Delete\n\t4.Exit");
        printf("\n Enter your choice: ");
        scanf("%d", &choice);
        switch(choice) {
            case 1:
                insert();
                break;

            case 2:
                display();
                break;

            case 3:
                delete_node();
                break;

            case 4:
                return;
        }
    }
}