// traverse the tree in in-order basis
// print the treee content in in-order basis
void inOrder(NodePtr node) {
	if (node != NULL) {
		inOrder(node->left);
		printf("%s ", node->data.word);
		inOrder(node->right);
	}
}

// traverse the tree in post-order basis
// print the treee content in post-order basis
void postOrder(NodePtr node) {
	if (node != NULL) {
		postOrder(node->left);
		postOrder(node->right);
		printf("%s ", node->data.word);
	}
}

// pre order traversal
void preOrder(NodePtr node) {

if (node != NULL) {
printf(“%s “, node->data.word);
preOrder(node->left);
preOrder(node->right);
}

}

If binary tree is empty, create a node, and assign data, point to it
Otherwise : point to root node

Compare the new – data – to – insert with the current node data
We maintain a pointer say current to point to the node under visit

If data matched : nothing to do
If data does not match :
keep traversing left if new data is smaller than current node data(until match or reach leaf / null).

To keep traversing to the left : current = current->left
Then create a new node, and point the left of curr node to this new node

keep traversing right if new data is bigger than current node data(until match or reach leaf / null).

To keep traversing to the right : current = current->right
Then create a new node, and point the right of current node to this new node

•Search the Hash

•Read a number/word

•From the user

•Find the position for this number/word

•in the graph (vertical array of nodes)

•By dividing with N or similar

•Check if any vertex node is there

•In that array position (array of graph vertices)

•If no vertex is there

•The word is not in the hash

•If a vertex is there

•Match with the vertex label, if matched you found the word/number

•If  no match with the vertex labels

•traverse through the edges

•Until you find a match

•How to Build

•Build the Hash

•Read a number/word from file

•Find the position for this number/word

•in the graph (vertical array of nodes)

•By dividing with N or similar

•Check if any vertex node is there

•In that array position (array of graph vertices)

•If no vertex is there

•Create a vertex node, assign the number/word to that node

•Insert into that position

•If a vertex is there

•If no edge so far, create an edge node, assign number/word

•Else: traverse through the edges

•Go to the end of the edge list

•Create an edge vertex, assign the number/word to that edge node

•

•Build the Hash

•Read a number/word from file

•Find the position for this number/word

•in the graph (vertical array of nodes)

•By dividing with N or similar

•Check if any vertex node is there

•In that array position (array of graph vertices)

•If no vertex is there

•Create a vertex node, assign the number/word to that node

•Insert into that position

•If a vertex is there

•If no edge so far, create an edge node, assign number/word

•Else: traverse through the edges

•Go to the end of the edge list

•Create an edge vertex, assign the number/word to that edge node

•

#include <iostream>
#include <string.h>
#include <stdlib.h>

#pragma warning(disable : 4996)

#define MaxWordSize 100

// Declare a structure that holds data in a node
typedef struct {
	char word[MaxWordSize + 1];
} NodeData;

typedef struct treeNode {
	NodeData data;
	struct treeNode* left, * right;
} TreeNode, *TreeNodePtr;

typedef struct {
	TreeNodePtr root;
} BinaryTree;

TreeNodePtr buildTree(FILE *in) {

	char str[MaxWordSize + 1];
	
	//read one word from the file
	fscanf_s (in, "%s", str);

	//if we see @ then return null (end of current recursion)
	if (strcmp (str, "@") == 0) return NULL;

	//allocate space for a TreeNode
	TreeNodePtr p = (TreeNodePtr) malloc (sizeof(TreeNode));

	// copy the data to the tree node
	strcpy_s (p->data.word, str);

	// build the left sub tree using recursion
	p->left = buildTree(in);

	// build the right sub tree using recursion
	p->right = buildTree(in);

	return p;

} //end buildTree


// traverse the tree in in-order basis
// print the treee content in in-order basis
void inOrder(TreeNodePtr node) {	
	//printf("%s ", node->data.word);
	if (node != NULL) {
		inOrder(node->left);
		printf("%s ", node->data.word);
		inOrder(node->right);
	}
} //end inOrder


// main method
int main(){

	// declare a binary tree
	BinaryTree bt;

	//open the file where tree data are kept
	FILE *in = fopen("btree.in", "r");
	
	// build the tree
	bt.root = buildTree(in);

	inOrder(bt.root);

}

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

// Declare a structure that holds data in a node
typedef struct {
	int num;
} NodeData;

typedef struct treeNode {
	NodeData data;
	struct treeNode* left, * right;
} TreeNode, *TreeNodePtr;

typedef struct {
	TreeNodePtr root;
} BinaryTree;

// main method
int main()
{
	// NULL Pointing binary tree 
	BinaryTree bt1;
	bt1.root = NULL;

	//Binary tree with one Root Node
	TreeNodePtr p = (TreeNodePtr) malloc(sizeof(TreeNode));
	p->data.num = 5000;
	p->left = NULL;
	p->right = NULL;
	bt1.root = p;

	//pointers in C
	//https://www.geeksforgeeks.org/null-pointer-in-c/

}

#include <iostream>
#include <string.h>

#pragma warning(disable : 4996)
#define MaxWordSize 100

// Declare a structure that holds data in a node
typedef struct {
	int num;
} NodeDataInt;

// Declare a structure that holds data in a node
typedef struct {
	char word[MaxWordSize + 1];
	int freq;
} NodeDataChar;


// define what a node will look like
typedef struct treenodeInt {
	NodeDataInt data;
	struct treenode* left, * right;
} t2;

// define what a node will look like
typedef struct treenodeChar {
	NodeDataChar data;
	struct treenode *left, *right;
} t3;


// main method
int main()
{
	// Node with integer data
	NodeDataInt aNode;
	aNode.num = 100;
	std::cout << "aNode.num: " << aNode.num << "\n";
	
	// Node with character data
	NodeDataChar aNodeChar;
	strcpy(aNodeChar.word, "Hello Word");
	std::cout << "aNodeChar.word: " << aNodeChar.word << "\n";

	//syntax error
	//t2.data.num = 1000;

	// example using tree node with int data
	t2 aTNode;
	aTNode.data.num = 1000;
	std::cout << "aTNode.data.num: " << aTNode.data.num << "\n";

	// example using tree node with char data
	t3 aTNodeChar;
	strcpy(aTNodeChar.data.word, "1000 Hello Node Char Data");
	std::cout << "aTNodeChar.data.word: " << aTNodeChar.data.word << "\n";

	
}