Code:
#include stdio.h
#include stdlib.h
#include string.h
#define MAX 30
struct emp_data
{
int empno;
char empName[MAX];
char designation[MAX];
struct emp_data *next;
};
/* ********************************************************************/
/* Function to insert a node at the front of the linked list. */
/* front: front pointer, id: employee ID, name: employee name */
/* desg: Employee designation */
/* Returns the new front pointer. */
/* ********************************************************************/
struct emp_data *insert(struct emp_data *front, int id, char name[],
char desg[])
{
struct emp_data *newnode;
newnode = (struct emp_data*)malloc(sizeof(struct emp_data));
if (newnode == NULL)
{
printf("\n Allocation failed \n");
exit(2);
}
newnode->empno = id;
strcpy(newnode->empName, name);
strcpy(newnode->designation, desg);
newnode->next = front;
front = newnode;
return(front);
}
/* End of insert() */
/* Function to display a node in a linked list */
void printNode(struct emp_data *p)
{
printf("\n Employee Details...\n");
printf("\n Emp No : %d", p->empno);
printf("\n Name : %s", p->empName);
printf("\n Designation : %s\n", p->designation);
printf("-------------------------------------\n");
}
/* End of printNode() */
/* ********************************************************/
/* Function to deleteNode a node based on employee number */
/* front: front pointer, id: Key value */
/* Returns: the modified list. */
/* ********************************************************/
struct emp_data* deleteNode(struct emp_data *front, int id)
{
struct emp_data *ptr;
struct emp_data *bptr;
if (front->empno == id)
{
ptr = front;
printf("\n Node deleted:");
printNode(front);
front = front->next;
free(ptr);
return(front);
}
for (ptr = front->next, bptr = front; ptr != NULL; ptr = ptr->next,
bptr = bptr->next)
{
if (ptr->empno == id)
{
printf("\n Node deleted:");
printNode(ptr);
bptr->next = ptr->next;
free(ptr);
return(front);
}
}
printf("\n Employee Number %d not found ", id);
return(front);
}
/* End of deleteNode() */
/* ****************************************************************/
/* Function to search the nodes in a linear fashion based emp ID */
/* front: front pointer, key: key ID. */
/* ****************************************************************/
void search(struct emp_data *front, int key)
{
struct emp_data *ptr;
for (ptr = front; ptr != NULL; ptr = ptr -> next)
{
if (ptr->empno == key)
{
printf("\n Key found:");
printNode(ptr);
return;
}
}
printf("\n Employee Number %d not found ", key);
}
/* End of search() */
/* Function to display the linked list */
void display(struct emp_data *front)
{
struct emp_data *ptr;
for (ptr = front; ptr != NULL; ptr = ptr->next)
{
printNode(ptr);
}
}
/* End of display() */
/* Function to display the menu of operations on a linked list */
void menu()
{
printf("---------------------------------------------\n");
printf("Press 1 to INSERT a node into the list \n");
printf("Press 2 to DELETE a node from the list \n");
printf("Press 3 to DISPLAY the list \n");
printf("Press 4 to SEARCH the list \n");
printf("Press 5 to EXIT \n");
printf("---------------------------------------------\n");
}
/* End of menu() */
/* Function to select the option */
char option()
{
char choice;
printf("\n\n>> Enter your choice: ");
switch(choice=getche())
{
case '1':
case '2':
case '3':
case '4':
case '5': return(choice);
default : printf("\n Invalid choice.");
}
return choice;
}
/* End of option() */
/* The main() program begins */
void main()
{
struct emp_data *linkList;
char name[21], desig[51];
char choice;
int eno;
linkList = NULL;
printf("\n Welcome to demonstration of singly linked list \n");
menu();
do
{
/* choose oeration to be performed */
choice = option();
switch(choice)
{
case '1':
printf("\n Enter the Employee Number : ");
scanf("%d", &eno);
printf("Enter the Employee name : ");
fflush(stdin);
gets(name);
printf("Enter the Employee Designation : ");
gets(desig);
linkList = insert(linkList, eno, name, desig);
break;
case '2':
printf("\n\n Enter the employee number to be deleted: ");
scanf("%d", &eno);
linkList = deleteNode(linkList, eno);
break;
case '3':
if (linkList == NULL)
{
printf("\n List empty.");
break;
}
display(linkList);
break;
case '4':
printf("\n\n Enter the employee number to be searched: ");
scanf("%d", &eno);
search(linkList, eno);
break;
case '5': break;
}
} while (choice != '5');
}
Output:
Welcome to demonstration of singly linked list
---------------------------------------------
Press 1 to INSERT a node into the list
Press 2 to DELETE a node from the list
Press 3 to DISPLAY the list
Press 4 to SEARCH the list
Press 5 to EXIT
---------------------------------------------
>> Enter your choice: 1
Enter the Employee Number : 12
Enter the Employee name : ram
Enter the Employee Designation : HR
>> Enter your choice: 3
Employee Details...
Emp No : 12
Name : ram
Designation : HR
-------------------------------------
>> Enter your choice:
Invalid choice.
>> Enter your choice: 4
Enter the employee number to be searched: 12
Key found:
Employee Details...
Emp No : 12
Name : ram
Designation : HR
-------------------------------------
>> Enter your choice:
Invalid choice.
>> Enter your choice: 2
Enter the employee number to be deleted: 12
Node deleted:
Employee Details...
Emp No : 12
Name : ram
Designation : HR
-------------------------------------
>> Enter your choice:
Invalid choice.
>> Enter your choice: 4
Enter the employee number to be searched: 1
Employee Number 1 not found
>> Enter your choice:
Invalid choice.
>> Enter your choice: 5
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