#include<stdio.h>
#include<string.h>
#include<stdlib.h>
int count=0;
struct node
{
struct node *prev;
int ssn,phno;
float sal;
char name[20],dept[10],desg[20];
struct node *next;
}*beg=NULL,*temp=NULL,*last=NULL;
void create()
{
int ssn,phno;
float sal;
char name[20],dept[10],desg[20];
temp =(struct node *)malloc(sizeof(struct node));
temp->prev = NULL;
temp->next = NULL;
printf("\n Enter ssn,name,department, designation, salary and phno of employee : ");
scanf("%d %s %s %s %f %d", &ssn, name,dept,desg,&sal, &phno);
temp->ssn = ssn;
strcpy(temp->name,name);
strcpy(temp->dept,dept);
strcpy(temp->desg,desg);
temp->sal = sal;
temp->phno = phno;
count++;
}
void insertbeg()
{
create();
if (beg == NULL)
{
beg = temp;
last = beg;
}
else
{
temp->next = beg;
beg->prev = temp;
beg = temp;
}
}
void insertend()
{
create();
if(beg==NULL)
{
beg = temp;
last = beg;
}
else
{
last->next = temp;
temp->prev = last;
last = temp;
}
}
void displaybeg()
{
temp=beg;
printf("\n Linked list elements from begining : \n");
while (temp!= NULL)
{
printf("%d %s %s %s %f %d\n", temp->ssn, temp->name,temp->dept,temp->desg,temp->sal, temp->phno );
temp = temp->next;
}
printf(" No of employees = %d ", count);
}
void deleteend()
{
printf("%d %s %s %s %f %d\n", last->ssn, last->name,last->dept,last->desg,last->sal, last->phno );
if(last->prev==NULL)
{
beg=NULL;
last=NULL;
}
else
{
last=last->prev;
last->next=NULL;
}
count--;
}
void deletebeg()
{
printf("%d %s %s %s %f %d", beg->ssn, beg->name,beg->dept,beg->desg,beg->sal, beg->phno );
if(beg->next==NULL)
{
beg=NULL;
last=NULL;
}
else
{
beg=beg->next;
}
count--;
}
int main()
{
int ch,n,i;
while (1)
{
printf("\n-----------------MENU--------------------\n");
printf("\n 1 - create a DLL of n emp");
printf("\n 2 - Display from beginning");
printf("\n 3 - Insert at end");
printf("\n 4 - delete at end");
printf("\n 5 - Insert at beg");
printf("\n 6 - delete at beg");
printf("\n 7 - exit\n");
printf("------------------------------------------\n");
printf("\n Enter choice : ");
scanf("%d", &ch);
switch (ch)
{
case 1:printf("\n Enter no of employees : ");
scanf("%d", &n);
for(i=0;i<n;i++)
insertend();
break;
case 2:if(beg == NULL)
printf("List is empty \n");
else
displaybeg();
break;
case 3: insertend();
break;
case 4:if(beg == NULL)
printf("List is empty \n");
else
deleteend();
break;
case 5:insertbeg();
break;
case 6:if(beg == NULL)
printf("List is empty \n");
else
deletebeg();
break;
case 7:exit(0);
default: printf("invalid choice\n");
}
}
}

C Language online compiler

Write, Run & Share C Language code online using OneCompiler's C online compiler for free. It's one of the robust, feature-rich online compilers for C language, running the latest C version which is C18. Getting started with the OneCompiler's C editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'C' and start coding!

Read inputs from stdin

OneCompiler's C online editor supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample C program which takes name as input and print your name with hello.

#include <stdio.h>
int main()
{
    char name[50];
    printf("Enter name:");
    scanf("%s", name);
    printf("Hello %s \n" , name );
    return 0;
    
}

About C

C language is one of the most popular general-purpose programming language developed by Dennis Ritchie at Bell laboratories for UNIX operating system. The initial release of C Language was in the year 1972. Most of the desktop operating systems are written in C Language.

Key features:

  • Structured Programming
  • Popular system programming language
  • UNIX, MySQL and Oracle are completely written in C.
  • Supports variety of platforms
  • Efficient and also handle low-level activities.
  • As fast as assembly language and hence used as system development language.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition if-else is used.

if(conditional-expression) {
   // code
} else {
   // code
}

You can also use if-else for nested Ifs and if-else-if ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to if-else-if ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  // code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {  
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

One dimentional Array:

data-type array-name[size];

Two dimensional array:

data-type array-name[size][size];

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

Two types of functions are present in C

  1. Library Functions:

Library functions are the in-built functions which are declared in header files like printf(),scanf(),puts(),gets() etc.,

  1. User defined functions:

User defined functions are the ones which are written by the programmer based on the requirement.

How to declare a Function

return_type function_name(parameters);

How to call a Function

function_name (parameters)

How to define a Function

return_type function_name(parameters) {  
  //code
}