Question

Write a program in C as per following requirements:

a) It takes two fields from the user 1) NAME and 2) age. Hint: (Take the name of employee

in an array of 50 characters).

b) It saves the data given by the user in a doubly link list.

c) As soon a record is entered by the user it should be given a record number or serial

number.

d) Program should have a menu for

a. Entering new data.

b. Printing a particular record by serial number.

c. Printing the whole data with serial numbers.

d. Exit the program.

Answer 1

#include<stdio.h>
#include<string.h>
#include<stdlib.h>

int count=0;
struct node
{
    char name[50];
    int sno;
    int age;
    struct node *next;
    struct node *pre;
};
struct node *cur=NULL,*head=NULL;//head is the start node and cur is the current node
void add()/*function to add new nodes*/
{
    struct node *newnode=(struct node*) malloc(sizeof(struct node));
    char name[50];
    int age;
    printf("Enter the name :");
    scanf("%s",name);
    printf("Enter the age :");/*inputting name and age and assigning it to the node*/
    scanf("%d",&age);
    strcpy( newnode->name,name);
    newnode->age=age;
    count++;/*glogal variable which gets incremented when a new node comes*/
    newnode->sno=count;
    if(head==NULL)
    {
        head=newnode;  /*checks if head is null. then assign it is assigned with new node*/
        head->pre=NULL;
        head->next=head;
        cur=head;
        
    }
    else
    {
        newnode->pre=cur;
        newnode->next=NULL;/*current node'snextis assigned to new node.previousnode's next is assigned to current node*/
        cur->next=newnode;
        cur=newnode;/*new node is assigned tocurrent node to keep track of nodes*/
    }
    
    
}

void displayslno(int sno)
{
    struct node *temp=head;
    int f=0;
    while(temp!=NULL)/*loop through all nodes*/
    {
        if(temp->sno==sno)/*checks if sno entered equals node's sno*/
        {
        printf("\nSerial Number : %d",temp->sno);
        printf("\nName :%s",temp->name);
        printf("\nAge :%d",temp->age);
        temp=temp->next;
        f=1;/*flag to check if the condition satisfies*/
        break;
        }
       
    }
    if(f==0)
    {
        printf("\nInvalid Serail Number\n");
    }
}

void display()
{
    struct node *temp=head;/*function to display all nodes*/
    while(temp!=NULL)
    {
        printf("\nSerial Number : %d",temp->sno);
        printf("\nName : %s",temp->name);
        printf("\nAge : %d",temp->age);
        temp=temp->next;
    }
}

int main()
{
    
    struct node *new_nd = (struct node*) malloc(sizeof(struct node));
    
    int sno;
    int ch,choice;
    do
    {
       printf("Press options(1/2/3/4)\n1.Enter new data\n2. display a single record\n3.Display entire data\n4.Exit\n");
    scanf("%i",&ch);
   
    switch(ch)
    {
        case 1:add();
               break;
        case 2:printf("Enter the slno:");
                scanf("%i",&sno);
                displayslno(sno);
               break;
        case 3:display();
               break;
        case 4:printf("Exiting!!!");
                break;
        default:printf("Invalid Choice\n");       
    }
    if(ch!=4)
    {
    printf("\nPress 1 to continue\n");
    scanf("%d",&choice);
    }
    }while((choice==1)&&(ch!=4));
    
    return 0;
}