bool isBST2(TreeNode* root, int l , int r) {
if (!root) return true;
if (root->val > r || root->val < l) return false;
if (!isBST2(root->left, l, root->val)) return false;
if (!isBST2(root->right, root->val+1, r)) return false;
return true;
}
int isBST2(struct node* head,int min,int max){
if(!head){
return 1;
}
if(head->data < min || head->data > max){
return 0;
}
return(isBST2(head->left,min,head->data) && isBST2(head->right,head->data,max));
}
isBST2(BinaryTreeNode * pRoot, int & lowerValue)
{
if (pRoot==NULL) return true;
if (!isBST2(pRoot->left, lowerValue))
return false;
if (pRoot->nValue <= lowerValue)
return false;
lowerValue=pRoot->nValue;
if (!isBST2(pRoot->right, lowerValue))
return false;
}
main() {
struct node *root = NULL;
int value;
root = plain_binary_tree();
printf("Initial Tree \n");
print(root);
value= isBST2(root);
if (value == 1)
printf("Yes..It's Binary Search Tree.\n");
else
printf("It's not a binary search Tree.\n");
}
bool isBst2(TreeNode* root) {
return isBST2(root, INT_MIN, INT_MAX);
}
