#include <stdio.h>
#include <stdlib.h>
struct Node
{
  int data;
  struct Node* next;
};

//Print the list 
void printthelist(struct Node* ptr)
{
  struct Node* printptr = ptr;
    printf("test string\n");
  while(printptr != NULL)
  {
    printf("%d\n",printptr->data);
    printptr=printptr->next;
  }
}

//Insert Node at end
void insertNodeEnd(struct Node** head,int data)
{
  struct Node* newnode = (struct Node*)malloc(sizeof(struct Node));
  newnode->data=data;
  newnode->next=NULL;
  struct Node* last= *head;
  
  if(*head==NULL)
  {
    *head=newnode;
  }
  else
  {
    while((last->next)!=NULL)
    {
        last=last->next;
    }
    last->next=newnode;
  }
  return;
}

//Insert Node at between
void insertinbetween(struct Node* prevnode, int data)
{
    struct Node* newnode = (struct Node*)malloc(sizeof(struct Node));
    newnode->data=data;
    
    if (prevnode ==NULL)
    {
      return;
    }
    else
    {
      newnode->next=prevnode->next;
      prevnode->next=newnode;
    }
}

//Insert Node at start
void insertNodeStart(struct Node** head,int data)
{
  struct Node* newnode = (struct Node*)malloc(sizeof(struct Node));
  newnode->data=data;
  newnode->next=*head;
  *head=newnode;
}

//Count nodes 
int lengthll(struct Node *head)
{
  int len=0;
  struct Node* cpyptr= head;
  while(cpyptr !=NULL)
  {
    len++;
    cpyptr = cpyptr->next;
  }
  return len;
}
void deleteNode(struct Node** head , int key)
{
  struct Node* cpyptr = *head,*prev;
  
  //empty linked list 
  if (cpyptr==NULL)
  {
    return;
  }
  
  //1st node is match 
  if(cpyptr!=NULL && (key==(cpyptr->data)))
  {
   *head=cpyptr->next;
   free(cpyptr);
   return;
  }
  
  //search for match of key 
  while(cpyptr!=NULL && (key != (cpyptr->data)))
  {
    prev=cpyptr;
    cpyptr=cpyptr->next;
  }
  
  //delete the node 
  prev->next=cpyptr->next;
  free(cpyptr);
}

int main()
{
  struct Node* head = NULL;
  insertNodeStart(&head,1);
    printthelist(head);

  insertNodeEnd(&head,5);
    printthelist(head);

  insertNodeStart(&head,2);
  printthelist(head);
  insertinbetween(head->next,7);
    printthelist(head);
    int len=0;
    len=lengthll(head);
        printf("%d\n",len);

deleteNode(&head,7);
    printthelist(head);

}

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
}