You are given a partially completed program that creates a list of patients, like patients' record.// Each record has this information: employee's name, supervisors's name, department of the employee, room number.// The struct 'employeeRecord' holds information of one employee. Department is enum type.// An array of structs called 'list' is made to hold the list of employees.// To begin, you should trace through the given code and understand how it works.// Please read the instructions above each required function and follow the directions carefully.// You should not modify any of the given code, the return types, or the parameters, you risk getting compile error.// You are not allowed to modify main ().// You can use string library functions. int main(){ char* fileName = "Employee_List. txt"; load(fileName); // load list of employees from file (if it exists). Initially there will be no file. char choice = 'i'; // initialized to a dummy value do { printf("\nEnter your selection:\n"); printf("\t a: add a new employee\n"); printf("\t d: display employee list\n"); printf("\t r: remove an employee from list\n"); printf("\t s: sort employee list by ID\n"); printf("\t q: quit\n"); choice = getchar(); flushStdIn(); executeAction(choice); } while (choice != 'q'); save(fileName); // save list of employees to file (overwrites file, if it exists) return 0;}// flush out leftover '\n' charactersvoid flushStdIn(){ char c; do c = getchar(); while (c != '\n' && c != EOF);}// ask for details from user for the given selection and perform that actionvoid executeAction(char c){ char employeeName_input[MAX_NAME_LENGTH] , supervisorName_input[MAX_NAME_LENGT H]; unsigned int roomNumber_input, idNumber_input, add_result= 0; char department_input[20]; switch (c) { case 'a': // input employee record from user printf("\nEnter employee name: "); fgets(employeeName_input, sizeof(employeeName_input), stdin); employeeName_input[strlen(employeeN ame_input) - 1] = '\0'; // discard the trailing '\n' char printf("Enter supervisor name: "); fgets(supervisorName_input, sizeof(supervisorName_input), stdin); supervisorName_input[strlen(supervi sorName_input) - 1] = '\0'; // discard the trailing '\n' char printf("Enter whether employee is in 'HR' or 'Marketing' or 'IT': "); fgets(department_input, sizeof(department_input), stdin); department_input[strlen(department_ input) - 1] = '\0'; // discard the trailing '\n' char printf("Please enter employee ID number: "); scanf("%d", &idNumber_input); printf("Please enter room number: "); scanf("%d", &roomNumber_input); flushStdIn(); // add the employee to the list add_result = add(employeeName_input, supervisorName_input, department_input, idNumber_input, roomNumber_input); if (add_result == 0) printf("\nEmployee is already on the list! \n\n"); else if (add_result == 1) printf("\nEmployee successfully added to the list! \n\n"); else printf("\nUnable to add. Employee list is full! \n\n"); break; case 'r': printf("Please enter ID number of employee to be deleted: "); scanf("%d", &idNumber_input); flushStdIn(); int delete_result = delete(idNumber_input); if (delete_result == 0) printf("\nEmployee not found in the list! \n\n"); else printf("\nEmployee deleted successfully! \n\n"); break; case 'd': display(); break; case 's': sort(); break; case 'q': break; default: printf("%c is invalid input!\n", c);