Event Management System.c

/* <Libaries> */
#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include <Windows.h>
#include<string.h>
/* </Libaries> */

/* <Clears buffers on Std.Input Stream> */
#define flush fflush(stdin)
/* </Clears buffers on Std.Input Stream> */

/* <Node Structure of BST Typedef as Node> */
typedef struct node {
	char name[50];
	int number;
	int event_registered[3];
	int unique_id;
	struct node *left;
	struct node *right;
	struct node *middle;
	struct node *parent;
} node;
/* </Node Structure of BST Typedef as Node> */

/* <Some global varibles> */
int ans = 0;
int del = 0;
node *global_root;
FILE *fptr;
int unique_id_in = 0;
void print_pattern();
/* </Some global varibles> */

/* <Intro Screen> */
void intro()
{
	printf("Hello!\nWelcome to the event management system!\n");
	printf("This program is created by \n");
	printf("\t19bce167 Divya Patel\n");
	printf("\t19bce172 Het Patel\n");
	printf("\t19bce175 Hrushi Patel\n");
	printf("Press 1 to continue\n>>>");
	int key = 0;
	while (key != 1)
	{
		scanf("%d", &key);
	}
	system("cls");
	return;
}
/* </Intro Screen> */

/* <Exit Confirmation Screen> */
int confirm_on_leave()
{
	printf("Are you sure you want to leave?\n");
	printf("Enter Y/y for Yes and another key for No\n>>>");
	char key;
	flush;
	scanf("%c", &key);
	if (key == 'Y' || key == 'y')
	{
		printf("Exiting program...\n");
		return 0;
	}
	else
		return -1;
}
/* </Exit Confirmation Screen> */

/* Function to Clear Array Which Is Used For Taking Input of Event Registered or Not*/
void clear_array(int *arr)
{
	int i;
	for (i = 0; i < 3; i++)
		arr[i] = 0;
}

/*Function to allocate space in heap memory for a node*/
node *newNode(char name_in[], int number_in, int *arr)
{
	node *temp =  (node *)malloc(sizeof(node));
	strcpy(temp->name, name_in);
	temp->number = number_in;
	for (int i = 0; i < 3; i++)
	{
		temp->event_registered[i] = arr[i];
	}
	temp->unique_id = unique_id_in;
	temp->left = temp->right = temp->middle = temp->parent = NULL;
	return temp;
}

/*Function to insert a entry*/
//Working -> Goes to left or right according to higher or lower value of key(key is here name);
//If same node with key (name) is found then the new entry is inserted in a linkedlist type structure which will is created
//by the component node_name->middle of node structure
node * insert(node* root, char name_in[], int number_in, int *arr)
{
	if (root == NULL)
		return newNode(name_in, number_in, arr);
	if (strcmpi(name_in, root->name) == 0)
	{
		root->middle = insert(root->middle, name_in, number_in, arr);
		node *temp = root->middle;
		temp->parent = root;
	}
	else if (strcmpi(name_in, root->name) < 0)
	{
		root->left  = insert(root->left, name_in, number_in, arr);
		node *temp = root->left;
		temp->parent = root;
	}
	else if (strcmpi(name_in, root->name) > 0)
	{
		root->right = insert(root->right, name_in, number_in, arr);
		node *temp = root->right;
		temp->parent = root;
	}
	return root;
}

//Given a non-empty binary search tree, return the node with minimum
//key value found in that tree. Note that the entire tree does not
//need to be searched.
node * minValueNode(node* root)
{
	node* current = root;
	while (current && current->left != NULL)
		current = current->left;
	return current;
}

//Function to delete entries with multiple names
//Working - It goes deep in the list and gives unique id of each node, and asks user to insert
//unique id to delete that node. After deletion is called by user, the other node adjusts accordingly
//to the TO-BE-DELETED node position with address present in their structure and after arrangements,
//frees the memory of deleted node
void delete_multiple(node* root)
{
	printf("There are many entries of same name.\n");
	node *temp = root;
	while (root != NULL)
	{
		printf("\t%s %d\n", root->name, root->unique_id);
		root = root->middle;
	}
	while (1)
	{
		int flag = 0;
		root = temp;
		printf("Enter unique id to get the entry deleted.\n>>>");
		int id_in;
		flush;
		scanf("%d", &id_in);
		flush;
		while (root != NULL && root->unique_id != id_in)
		{
			root = root->middle;
		}
		if (root == NULL)
		{
			printf("Enter valid id.\n>>>");
			continue;
		}
		else
		{
			if (root == temp)
			{
				root->middle->right = root->right;
				root->middle->left = root->left;
				if (root == global_root)
				{
					global_root = root->middle;
				}
				else
				{
					if (root->parent->left == root)
					{
						root->parent->left = root->middle;
					}
					else if (root->parent->right == root)
					{
						root->parent->right = root->middle;
					}
				}
				free(root);
			}
			else
			{
				root->parent->middle = root->middle;
				temp = root->middle;
				free(root);
			}
			break;
		}
	}
}
// Generel Function to delete entries
//Working - Explained in line comments
void deleteNode(node *t, char key[])                               //deletenumber function  for deleting node from tree
{
	del = 0;
	while (t != NULL)                                              //loop will run till last node
	{
		if (strcmpi(key, t->name) == 0 && t->middle == NULL)       //if node found in tree
		{
			if (t->left == NULL && t->right == NULL)               //if both node don't have both child
			{
				if (t == global_root)                              //if it is root and alone in tree
				{
					global_root = NULL;                            //make root null
				}
				else if (t->parent->left == t)                     //if it is left child of its parent node
				{
					t->parent->left = NULL;                        //make null parent's lchild to null
				}
				else                                               //if it is right child of parent node
				{
					t->parent->right = NULL;                       //then make parent's right child to null
				}
				free(t);
			}
			else if (t->left != NULL && t->right != NULL)          //if it has both the child
			{
				struct node *e;
				e = t->right;                                       //shift t to its right child
				if (e != NULL)                                      //if it is not null
				{
					while (e->left != NULL)                         //then goto left most child of t
					{
						e = e->left;
					}
				}

				if (t == global_root)
				{

					if (t->right == e)
					{
						e->left = t->left;
						e->parent = NULL;
					}
					else
					{
						e->parent->left = NULL;
						e->parent = NULL;
						e->left = t->left;
						e->right = t->right;
					}
					global_root = e;

				}
				else
				{
					int y = 0;
					if (e->parent->left == e)
					{
						e->parent->left = NULL;
					}
					else
					{
						e->parent->right = NULL;
						y = 1;
					}
					e->parent = t->parent;
					if (t->parent->left == t)
						t->parent->left = e;
					else
						t->parent->right = e;
					if (y == 1)
						e->left = t->left;
					else
					{
						e->left = t->left;
						e->right = t->right;
					}
				}

				free(t);
				if (e->left)
					e->left->parent = e;
				if (e->right)
					e->right->parent = e;

			}
			else                                                   //else part if it has only one child
			{
				if (t == global_root)                              //if node found is root
				{
					if (t->left)                                   //if node has left child
					{
						global_root = t->left;                     //update root to its left child
					}
					else                                           //if it has right child
					{
						global_root = t->right;                    //update root to its right child
					}
					free(t);
					global_root->parent = NULL;
				}
				else if (t->parent->left == t)                     //if it is not root and it is left child of parent node
				{
					if (t->left == NULL)                           //if it has right child
					{
						t->parent->left = t->right;                //make parent's left child to current node's right child
						t->right->parent = t->parent;
					}
					else                                           //if it has left child
					{
						t->parent->left = t->left;                 //make parent's left child to current node's left child
						t->left->parent = t->parent;
					}
					free(t);
				}
				else if (t->parent->right == t)                    //else part if it is right child of parent node
				{
					if (t->left == NULL)                           //if current node's has right child
					{
						t->parent->right = t->right;               //then make current nodes right child as parent's richild
						t->right->parent = t->parent;
					}
					else
					{
						t->parent->right = t->left;                //else make it left child of parent node
						t->left->parent = t->parent;
					}
					free(t);
				}
			}
			del = 1;                                               //make i to 1 to know that we deleted node
			break;                                                 //break the loop after deletion
		}
		else if (strcmpi(key, t->name) == 0 && t->middle != NULL)
		{
			delete_multiple(t);
			del = 1;
			break;
		}
		else if (strcmpi(key, t->name) < 0)                        //if our name is greater then current node's name
		{

			t = t->left;                                           //and update t to its left child
		}
		else                                                       //else part if it is lesser then current node
		{

			t = t->right;                                          //and shift t to its right child
		}
	}
	if (del == 0)                                                  //if after completion of loop name not found then print message
		printf("System Message::::%s Not Found.\n", key);

}

//Function to edit data of a entry
void edit(node *root)
{
	int key = -1;
	while (key != 0)
	{
		printf("Enter 1 to edit mobile number.\n");
		printf("Enter 2 to edit events registered.\n");
		printf("Enter 0 if you dont want to edit further.\n>>>");
		scanf("%d", &key);
		if (key > 2)
		{
			printf("Enter valid choice.\n>>>");
			continue;
		}
		if (key == 1)
		{
			printf("Enter new number.\n>>>");
			int number_in;
			scanf("%d", &number_in);
			root->number = number_in;
			printf("System Message::::Mobile number changed sucessfully!\n");
		}
		else if (key == 2)
		{
			printf("Enter which index number of event to view current status.\n>>>");
			int event_in;
			scanf("%d", &event_in);
			printf("%d event is ", event_in);
			if (root->event_registered[event_in] == 0)
			{
				printf("unregistered.\n");
			}
			else
			{
				printf("registered.\n");
			}
			printf("Press Y/y to alternate, any other key to skip.\n>>>");
			char c[10];
			flush;
			gets(c);
			flush;
			if (c[0] == 'Y' || c[0] == 'y')
			{
				root->event_registered[event_in] = !root->event_registered[event_in];
				printf("System Message::::Alternated sucessfully!\n");
			}
			else
			{
				printf("System Message::::Not Changed!\n");
			}
		}
		else
		{
			break;
		}
	}
}

//In case there are mulitple nodes of same name, then this function allows to change any of them
//with help of unique id
void edit_multiple(node *root)
{
	printf("There are many enteries of same name.\nEnter unique id to change particular information.\n>>>");
	node *temp = root;
	while (root != NULL)
	{
		printf("%s %d\n", root->name, root->unique_id);
		root = root->middle;
	}
	root = temp;
	int id;
	scanf("%d", &id);
	while (1)
	{
		while (root != NULL && root->unique_id != id)
		{
			root = root->middle;
		}
		if (root == NULL)
		{
			printf("Enter valid id.\n>>>");
			scanf("%d", &id);
		}
		else break;
	}
	edit(root);
}

//Funtion to search a node with particular name pass that node
// to edit or edit_multiple function according to needs
void edit_search(node* root, char name_in[])
{
	if (root == NULL)
		return;
	if (strcmpi(name_in, root->name) > 0)
		edit_search(root->right, name_in);
	else if (strcmpi(root->name, name_in) < 0)
		edit_search(root->left, name_in);
	else if (root->middle != NULL)
		edit_multiple(root);
	else
		edit(root);
}

//General function to search by name
void search(node* root, char name_in[])
{

	if (root == NULL)
		return;
	if (strcmpi(name_in, root->name) > 0)
		search(root->right, name_in);
	else if (strcmpi(root->name, name_in) < 0)
		search(root->left, name_in);
	else if (root != NULL && strcmpi(root->name, name_in) == 0)
	{
		printf("\t%s %d\n", root->name, root->number);
		ans++;
		search(root->middle, name_in);
	}
}

//General Funtion to Search by Number
void search_by_n(struct node *root, int ns)
{

	if (root != NULL)
	{
		if (root->number == ns)
		{
			printf("\t%s %d\n", root->name, root->number);
			ans++;
		}
		search_by_n(root->left, ns);
		search_by_n(root->middle, ns);
		search_by_n(root->right, ns);
	}
}

//Function which performs in-order traversal and prints data in
// ascending order of name entries
void inorder(node *root)
{
	if (root != NULL)
	{
		inorder(root->left);
		inorder(root->middle);
		printf("\t%-10s %-10d %-10d\n", root->name, root->number, root->unique_id);
		inorder(root->right);
	}
}

//Fucntion to save data in a file called output.txt
void file_print_all(node *root)
{

	if (root != NULL)
	{
		file_print_all(root->left);
		file_print_all(root->middle);
		fprintf(fptr, "%s %d\n", root->name, root->number);
		file_print_all(root->right);
	}
}

//Menu Function to simulate all the functions as per user needs
void menu()
{
	node *root = NULL;
	char name_in[50];
	int number_in;
	int event_registered_in[3];
	while (1)
	{

		system("cls");
		printf("---------Menu---------\n");
		printf("Enter 1 to Add New Participant.\n");
		printf("Enter 2 to Remove Participant.\n");
		printf("Enter 3 to Edit Existing Participant.\n");
		printf("Enter 4 to Veiw All Participants.\n");
		printf("Enter 5 to Print All Participants.\n");
		printf("Enter 6 to Search Participants.\n");
		printf("Enter 0 to Exit.\n");
		printf("----------------------\n>>>");

		char key[100];
		scanf("%s", key);
		if (key[0] == '0')
		{
			printf("System Message::::Saving your data before you plan to leave!\n...\n");
			fptr = fopen("output.txt", "w");
			file_print_all(root);
			fclose(fptr);
			printf("System Message::::Data saved!\n");
			key[0] = confirm_on_leave();
			if (key[0] == '0' )
				return;
			else
				continue;
		}
		else if (key[0] == '1')
		{
			clear_array(event_registered_in);
			printf("Enter name.\n>>>");
			flush;
			gets(name_in);
			flush;
			printf("Enter number.\n>>>");
			scanf("%d", &number_in);
			printf("Enter 1 to register in an event, any other key to skip the event.\n");
			for (int i = 0; i < 3; i++)
			{
				printf(">>>Event %2d : ", i + 1);
				int tmp;
				scanf("%d", &tmp);
				if (tmp == 1)
					event_registered_in[i] = 1;
				else
					event_registered_in[i] = 0;
			}
			if (root == NULL)
			{
				root = insert(root, name_in, number_in, event_registered_in);
				global_root = root;
			}
			else
				insert(root, name_in, number_in, event_registered_in);
			unique_id_in += 1;
		}
		else if (key[0] == '2')
		{
			if (global_root == NULL)                                      //if list is empty then print message
				printf("System Message::::Please first enter number, Your list is empty.\n");
			else
			{
				printf("Enter a name which you want to delete.\n");
				flush;
				gets(name_in);                               //user input to find name in list and delete
				flush;
				flush;
				deleteNode(root, name_in);                           //call to deletenumber function
				root = global_root;
				if (del != 0)
					printf("System Message::::Deleted Successfully.\n");
				del = 0;
			}
			continue;

		}
		else if (key[0] == '3')
		{
			if (global_root == NULL)                                      //if list is empty then print message
				printf("System Message::::Please first enter number, Your list is empty\n");
			else
			{
				printf("Enter a name which you want to edit\n>>>");
				flush;
				gets(name_in);                               //user input to find name in list and delete
				flush;
				edit_search(root, name_in);
			}
			continue;
		}
		else if (key[0] == '4')
		{
			if (global_root)
			{
				printf("\tName      Phone      Unique ID\n");
				inorder(root);
			}
			else
				printf("System Message::::Event List is empty\n");
		}
		else if (key[0] == '5')
		{
			fptr = fopen("output.txt", "w");
			file_print_all(root);
			fclose(fptr);
		}
		else if (key[0] == '6')
		{
			printf("Enter 1 to search by name.\nEnter 2 to search by number.\n>>>");
			int x;
			scanf("%d", &x);
			if (x == 1)
			{
				printf("Enter name\n>>>");
				flush;
				gets(name_in);
				search(root, name_in);
				if (ans == 0)
				{
					printf("System Message::::No matches found\n");
				}
				else
				{
					printf("System Message::::Finished viewing results\n");
					ans = 0;
				}
			}
			else
			{
				printf("Enter number.\n>>>");
				scanf("%d", &number_in);
				search_by_n(root, number_in);
				if (ans == 0)
				{
					printf("System Message::::No matches found\n");
				}
				else
				{
					printf("System Message::::Finished viewing results\n");
					ans = 0;
				}
			}
		}
		else
		{
			printf("System Message::::Please Enter A Valid Choice\n");
			continue;
		}
	}
}

//Function to print message after exiting
void exit_confirm()
{
	printf("Underlying Data Structures\n\tMain - BST\n\tSecondary - Linkedlist\n");
	printf("Time Complexities of Each Fucntions are below\n");
	printf("\t Insertion: Average-O(Log(n)), Worst-O(n)");
	printf("\t Deletion:  Average-O(Log(n)), Worst-O(n)");
	printf("\t Searching: Average-O(Log(n)), Worst-O(n)");
	printf("\t Searching: Average-O(Log(n)), Worst-O(n)");
	printf("The Worst Cases are the ones such that all users will have same name and ultimately linkedlist will be formed.\n");
	printf("The program has ended!\nFor the reference, the data is been stored in output.txt file!\n");
}

//Main Functions to call other functions
int main()
{
	intro();
	menu();
	exit_confirm();
}