BinaryTree.c

#define _CRT_SECURE_NO_WARNINGS

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

struct Node
{
	struct Node* lchild;
	int data;
	struct Node* rchild;
};
struct Queue
{
	int size;
	int front;
	int rear;
	Node** Q;
};
void create(struct Queue* q, int size)
{
	q->size = size;
	q->front = q->rear = 0;
	q->Q = (Node**)malloc(q->size * sizeof(Node*));
}
void enqueue(struct Queue* q, struct Node* x)
{
	if ((q->rear + 1) % q->size == q->front)
		printf("Queue is Full");
	else
	{
		q->rear = (q->rear + 1) % q->size;
		q->Q[q->rear] = x;
	}
}
struct Node* dequeue(struct Queue* q)
{
	struct Node* x = NULL;

	if (q->front == q->rear)
		printf("Queue is Empty\n");
	else
	{
		q->front = (q->front + 1) % q->size;
		x = q->Q[q->front];
	}
	return x;
}
int isEmpty(struct Queue q)
{
	return q.front == q.rear;
}
struct Node* root = NULL;
void Treecreate()
{
	struct Node* p, * t;
	int x;
	struct Queue q;
	create(&q, 100);
	printf("Enter root value");
	scanf("%d", &x);
	root = (struct Node*)malloc(sizeof(struct Node));
	root->data = x;
	root->lchild = root->rchild = NULL;
	enqueue(&q, root);
	while (!isEmpty(q))
	{
		p = dequeue(&q);
		printf("Enter left child of %d", p->data);
		scanf("%d", &x);
		if (x != -1)
		{
			t = (struct Node*)malloc(sizeof(struct Node));
			t->data = x;
			t->lchild = t->rchild = NULL;
			p->lchild = t;
			enqueue(&q, t);
		}
		printf("Enter right child %d", p->data);
		scanf("%d", &x);
		if (x != -1)
		{
			t = (struct Node*)malloc(sizeof(struct Node));
			t->data = x;
			t->lchild = t->rchild = NULL;
			p->rchild = t;
			enqueue(&q, t);
		}
	}
}
void Preorder(struct Node* p)
{
	if (p)
	{
		printf("%d ", p->data);
		Preorder(p->lchild);
		Preorder(p->rchild);
	}
}
void Inorder(struct Node* p)
{
	if (p)
	{
		Inorder(p->lchild);
		printf("%d ", p->data);
		Inorder(p->rchild);
	}
}
void Postorder(struct Node* p)
{
	if (p)
	{
		Postorder(p->lchild);
		Postorder(p->rchild);
		printf("%d ", p->data);
	}
}
int main(int argc, char* argv[]) {

	Treecreate();
	Preorder(root);
	printf("\nPost Order ");
	Postorder(root);
	return 0;
}