bst

tree.c

#import <stdio.h>
#import <stdlib.h>

typedef struct node
{
	int data;
	struct node *left;
	struct node *right;
} Node;


void preOrder(Node *node){
	if (node==NULL)
	{
		return;
	}
	printf("%d\n", node->data);
	preOrder(node->left);
	preOrder(node->right);
}

void inOrder(Node *node){
	if (node==NULL)
	{
		return;
	}
	inOrder(node->left);
	printf("%d\n", node->data);
	inOrder(node->right);
}

void postOrder(Node *node){
	if (node==NULL)
	{
		return;
	}
	postOrder(node->left);
	postOrder(node->right);
	printf("%d\n", node->data);
}

void buildSearchTree(Node *node, int data){
	if (data<node->data)
	{	
		// left
		if (node->left==NULL)	
		{
			Node *left = malloc(sizeof(Node));
			left->left=NULL;
			left->right=NULL;
			left->data = data;
			node->left = left;
		}else{
			buildSearchTree(node->left, data);
		}
	}
	else {
		// right
		if (node->right==NULL)	
		{
			Node *right = malloc(sizeof(Node));
			right->left=NULL;
			right->right=NULL;
			right->data = data;
			node->right = right;
		}else{
			buildSearchTree(node->right, data);
		}
	}

}

int main(){


	int arr[] = {1,3,2,4,6,5,7};
	int n = 7;

	Node node;
	node.left=NULL;
	node.right=NULL;
	node.data = arr[0];

	for (int i = 1; i < n; ++i)
	{
		buildSearchTree(&node, arr[i]);
	}
	postOrder(&node);
	return 0;
}