﻿ C : Delete a node from the middle of Singly Linked List

# C Exercises: Delete a node from the middle of Singly Linked List

## C Singly Linked List : Exercise-8 with Solution

Write a program in C to delete a node from the middle of a Singly Linked List.

Visual Presentation:

Sample Solution:

C Code:

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

struct node
{
int num;                    // Data of the node
struct node *nextptr;       // Address of the node
}*stnode;                       // Pointer to the starting node

// Function prototypes
void createNodeList(int n);      // Function to create the linked list
void MiddleNodeDeletion(int pos); // Function to delete a node from the middle
void displayList();              // Function to display the list

// Main function
int main()
{
int n, num, pos;
printf("\n\n Linked List : Delete a node from the middle of Singly Linked List. :\n");
printf("-------------------------------------------------------------------------\n");

printf(" Input the number of nodes : ");
scanf("%d", &n);
createNodeList(n);

printf("\n Data entered in the list are : \n");
displayList();

printf("\n Input the position of node to delete : ");
scanf("%d", &pos);

if (pos <= 1 || pos >= n)
{
printf("\n Deletion can not be possible from that position.\n ");
}
if (pos > 1 && pos < n)
{
printf("\n Deletion completed successfully.\n ");
MiddleNodeDeletion(pos);
}

printf("\n The new list are  : \n");
displayList();
return 0;
}

// Function to create a linked list with n nodes
void createNodeList(int n)
{
struct node *fnNode, *tmp;
int num, i;

stnode = (struct node *)malloc(sizeof(struct node));
if (stnode == NULL)             // Check whether stnode is NULL for memory allocation
{
printf(" Memory can not be allocated.");
}
else
{
printf(" Input data for node 1 : ");
scanf("%d", &num);

stnode->num = num;          // Assign data to the first node
tmp = stnode;

for (i = 2; i <= n; i++)
{
fnNode = (struct node *)malloc(sizeof(struct node));

if (fnNode == NULL)    // Check whether fnNode is NULL for memory allocation
{
printf(" Memory can not be allocated.");
break;
}
else
{
printf(" Input data for node %d : ", i);
scanf(" %d", &num);

fnNode->num = num;      // Assign data to the current node

tmp->nextptr = fnNode; // Links previous node i.e. tmp to the fnNode
tmp = tmp->nextptr;
}
}
}
}

// Function to delete a node from the middle of the list at a specific position
void MiddleNodeDeletion(int pos)
{
int i;
struct node *toDelMid, *preNode;

if (stnode == NULL)
{
printf(" There are no nodes in the List.");
}
else
{
toDelMid = stnode;
preNode = stnode;

// Traverse to the specified position in the list
for (i = 2; i <= pos; i++)
{
preNode = toDelMid;
toDelMid = toDelMid->nextptr;

if (toDelMid == NULL)
break;
}
if (toDelMid != NULL)
{
if (toDelMid == stnode)    // If the node to delete is the first node
stnode = stnode->nextptr;

preNode->nextptr = toDelMid->nextptr; // Adjust the pointers
toDelMid->nextptr = NULL;
free(toDelMid);           // Free memory of the deleted node
}
else
{
printf(" Deletion can not be possible from that position.");
}
}
}

// Function to display the linked list
void displayList()
{
struct node *tmp;

if (stnode == NULL)
{
printf(" No data found in the list.");
}
else
{
tmp = stnode;
while (tmp != NULL)
{
printf(" Data = %d\n", tmp->num);   // Print the data of the current node
tmp = tmp->nextptr;                 // Move to the next node
}
}
}
```
```

Sample Output:

```Linked List : delete a node from the middle of Singly Linked List. :
-------------------------------------------------------------------------
Input the number of nodes : 3
Input data for node 1 : 2
Input data for node 2 : 5
Input data for node 3 : 8

Data entered in the list are :
Data = 2
Data = 5
Data = 8

Input the position of node to delete : 2

Deletion completed successfully.

The new list are  :
Data = 2
Data = 8
```

Flowchart:

createNodeList() :

MiddleNodeDeletion() :

displayList() :

C Programming Code Editor:

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