Construct_BinaryTree.cpp

#include <iostream>
#include <climits>
using namespace  std;


class Node{

public:
	int data;
	Node *left,*right;
	Node(int val){
		data=val;
		left=right=NULL;
	}
};


Node *ConstructBST(int preorder[],int *idx,int key,int min,int max,int n){

	if(*idx>=n){
		return NULL;
	}

	Node *root=NULL;

	if(key>min && key<max){
		root=new Node(key);
		*idx=*idx+1;
		if(*idx<n){
			root->left=ConstructBST(preorder,idx,preorder[*idx],min,key,n);
		}
		if(*idx<n){
			root->right=ConstructBST(preorder,idx,preorder[*idx],key,max,n);
		}
	}
	return root;
}

void printPreorder(Node *root){
	if(root==NULL){
		return;
	}
	cout<<root->data<<" ";
	printPreorder(root->left);
	printPreorder(root->right);
}

int main(){


	int preorder[]={10,2,1,13,11};
	int n=5;
	int idx=0;
	Node *root=ConstructBST(preorder,&idx,preorder[0],INT_MIN,INT_MAX,n);
	printPreorder(root);



	return 0;

}