Linked List is another data structure consisting of group of nodes which together represent a sequence. Each node has two parts one for the value and other for link to the next node.
Linked lists allows dynamic memory allocation.
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| A singly linked list whose nodes contain two fields: an integer value and a link to the next node |
Some of the operations in a linked list are :
- Insertion into the list
- Deletion from the list
- Updation of the value
- Display the list
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Download codePROGRAM :
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
struct node
{
int value;
struct node *next;
};
typedef struct node snode;
snode *newnode, *ptr, *prev, *temp;
snode *first = NULL, *last = NULL;
int main()
{
int ch;
char ans = 'Y';
while (ans == 'Y'||ans == 'y')
{
printf("\n1.Insert node at first");
printf("\n2.Insert node at last");
printf("\n3.Insert node at position");
printf("\n4.Delete Node from any Position");
printf("\n5.Update Node Value");
printf("\n6.Display List");
printf("\n7.Exit\n");
printf("\nEnter your choice: \t");
scanf("%d", &ch);
switch (ch)
{
case 1:
insertNodeFirst();
break;
case 2:
insertNodeLast();
break;
case 3:
insertNodePosition();
break;
case 4:
deleteNode();
break;
case 5:
updateNode();
break;
case 6:
displayList();
break;
case 7:
return 0;
break;
default:
printf("\n...Invalid Choice...\n");
break;
}
printf("\nDo you want to continue ? (Y/N) \t");
scanf(" %c", &ans);
}
return 0;
}
snode* createNode(int val)
{
newnode = (snode *)malloc(sizeof(snode));
if (newnode == NULL)
{
printf("\nMemory was not allocated");
return 0;
}
else
{
newnode->value = val;
newnode->next = NULL;
return newnode;
}
}
void insertNodeFirst()
{
int val;
printf("\nEnter the value for the node: \t");
scanf("%d", &val);
newnode = createNode(val);
if (first == last && first == NULL)
{
first = last = newnode;
first->next = NULL;
last->next = NULL;
}
else
{
temp = first;
first = newnode;
first->next = temp;
}
printf("\nInserted Successfully");
}
void insertNodeLast()
{
int val;
printf("\nEnter the value for the Node: \t");
scanf("%d", &val);
newnode = createNode(val);
if (first == last && last == NULL)
{
first = last = newnode;
first->next = NULL;
last->next = NULL;
}
else
{
last->next = newnode;
last = newnode;
last->next = NULL;
}
printf("\nInserted Successfully");
}
void insertNodePosition()
{
int pos, val, count = 0, i;
printf("\nEnter the value for the Node: \t");
scanf("%d", &val);
newnode = createNode(val);
printf("\nEnter the position: \t");
scanf("%d", &pos);
ptr = first;
while (ptr != NULL)
{
ptr = ptr->next;
count++;
}
if (pos == 1)
{
if (first == last && first == NULL)
{
first = last = newnode;
first->next = NULL;
last->next = NULL;
}
else
{
temp = first;
first = newnode;
first->next = temp;
}
printf("\nInserted Successfully");
}
else if (pos>1 && pos<=count)
{
ptr = first;
for (i = 1; i < pos; i++)
{
prev = ptr;
ptr = ptr->next;
}
prev->next = newnode;
newnode->next = ptr;
printf("\nInserted Successfully");
}
else
{
printf("Position is out of range");
}
}
void deleteNode()
{
int pos, count = 0, i;
if (first == NULL)
{
printf("No nodes in the list to delete\n");
}
else
{
printf("\nEnter the position of value to be deleted: \t");
scanf(" %d", &pos);
ptr = first;
if (pos == 1)
{
first = ptr->next;
printf("\nElement deleted successfully");
}
else
{
while (ptr != NULL)
{
ptr = ptr->next;
count = count + 1;
}
if (pos > 0 && pos <= count)
{
ptr = first;
for (i = 1; i < pos; i++)
{
prev = ptr;
ptr = ptr->next;
}
prev->next = ptr->next;
}
else
{
printf("Position is out of range");
}
free(ptr);
printf("\nElement deleted successfully");
}
}
}
void updateNode()
{
int oldval, newval, flag = 0;
if (first == NULL)
{
printf("No nodes in the list to update\n");
}
else
{
printf("\nEnter the value to be updated: \t");
scanf("%d", &oldval);
printf("\nEnter the new value: \t");
scanf("%d", &newval);
for (ptr = first; ptr != NULL; ptr = ptr->next)
{
if (ptr->value == oldval)
{
ptr->value = newval;
flag = 1;
break;
}
}
if (flag == 1)
{
printf("\nUpdated Successfully");
}
else
{
printf("\nValue not found in List");
}
}
}
void displayList()
{
if (first == NULL)
{
printf("No nodes in the list to display\n");
}
else
{
for (ptr = first; ptr != NULL; ptr = ptr->next)
{
printf("%d\t", ptr->value);
}
}
}
Download codeOUTPUT :
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| C - Linked List Operations - Insertion at front |
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| C - Linked List Operations - Insertion at last and any position |
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| C - Linked List Operations - Deletion of node |
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| C - Linked List Operations - Updation of value |
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| C - Linked List Operations - Display List |
