added validate_bst.cpp

Author: sumeyyadede

validate_bst.cpp

@@ -0,0 +1,86 @@
+#include <iostream>
+
+using namespace std;
+
+template <class T>
+class Node{
+public:
+	Node();
+	~Node();
+	T data;
+	Node<T>* left;
+	Node<T>* right;
+};
+
+template <class T>
+Node<T>::Node(){
+	left = NULL;
+	right = NULL;
+}
+
+int lastItem = -1;
+bool validateBstLast(Node<int>* node){
+	if(node == NULL){
+		return true;
+	}
+	if(!validateBstLast(node->left)){
+		return false;
+	}
+	if(lastItem == -1){
+		lastItem = node->data;
+	}
+	else if(lastItem > node->data){
+		return false;
+	}
+	else{
+		lastItem = node->data;
+	}
+	if(!validateBstLast(node->right)){
+		return false;
+	}
+	return true;
+}
+
+bool validateBstMinMax(Node<int>* node, int mi = -1, int ma = -1){
+	if(node == NULL){
+		return true;
+	}
+	if((mi != -1 && mi > node->data) || (ma != -1 && ma < node->data) \
+		|| (!validateBstMinMax(node->left, mi, node->data))\
+		|| (!validateBstMinMax(node->right, node->data, ma))){
+		return false;
+	}
+	return true;
+}
+
+int main(){
+	
+ 	Node<int>* root = new Node<int>();
+	root->data = 15;
+	Node<int>* a = new Node<int>();
+	a->data = 8;
+	Node<int>* b = new Node<int>();
+	b->data = 20;
+	Node<int>* c = new Node<int>();
+	c->data = 5;
+	Node<int>* d = new Node<int>();
+	d->data = 10;
+	Node<int>* e = new Node<int>();
+	e->data = 16;
+	Node<int>* f = new Node<int>();
+	f->data = 30;
+	Node<int>* g = new Node<int>();
+	g->data = 7;
+	root->left = a;
+	root->right = b;
+	root->right->left = e;	
+	root->right->right = f;
+	root->left->left = c;
+	root->left->right = d;
+	root->left->right->left = g;
+
+	cout << validateBstLast(root) << endl;
+	cout << validateBstMinMax(root) << endl;
+
+	return 0;
+}