int checkBST(node *root, int min, int max)
{
if(root == 0)
return 1;
if(root->value > max || root->value < min)
return 0;
return (checkBST(root->left, min, root->value) && checkBST(root->right, root->value, max));
}
bool checkBST(TreeNode<T>* node) {
// value of left child must be less, value of the right one must be greater
if (node->left) {
if (node->left->value >= node->value)
return false;
if (!checkBST(node->left))
return false;
}
if (node->right) {
if (node->right->value < node->value)
return false;
if (!checkBST(node->right))
return false;
}
return true;
}
int checkBST(element *root, int left, int right) {
element *ele = root;
if(!ele)
return 1;
return (ele->data > left && ele->data < right && checkBST(ele->left, left, ele->data) && checkBST(ele->right,
ele->data, right));
}
main()
{
element *root = makeNode(50);
root->left = makeNode(25);
root->right = makeNode(75);
root->left->right = makeNode(60);
printf("%d\n", checkBST(root, INT_MIN, INT_MAX));
}
void ex4_5() {
std::cout << "ex4.5 \n";
std::vector<int> in;
for (int sample = 0; sample < std::rand() % 10000; ++sample)
in.push_back(std::rand() % 20);
std::sort(in.begin(), in.end());
auto node = createBST(in, 0, (int) in.size()) ;
// std::cout << " sample size=" << in.size() << ", max height = " << height << ", log(size)=" << log2(in.size()) << std::endl;
std::cout << "is it a BST? " << checkBST(node);
}
int checkBST(TreeNode *root, int min, int max)
{
if (root == NULL)
{
return 0;
}
if ((root->val < min) || (root->val > max))
{
return -1;
}
int left = checkBST(root->left, min, root->val);
int right = checkBST(root->right, root->val, max);
if (left == -1 || right == -1)
{
return -1;
}
return 1 + left + right;
}
void main()
{
node *root,*newroot;
root = getNode(4);
root->left = getNode(2);
root->right = getNode(5);
root->left->left = getNode(1);
root->left->right = getNode(3);
// global max and min int
printf("%s",checkBST(root,-32767,32767)?"true":"false");
newroot = getNode(3);
newroot->left = getNode(2);
newroot->right = getNode(5);
newroot->left->left = getNode(1);
newroot->left->right = getNode(4);
// global max and min int
printf("%s",checkBST(newroot,-32767,32767)?"true":"false");
}
void maxsub_BST_helper(TreeNode *root, int &res)
{
if (root == NULL)
{
return;
}
int ret = checkBST(root, INT_MIN, INT_MAX);
if ( ret != -1)
{
if(ret > res)
{
res = ret;
}
return;
}
maxsub_BST_helper(root->left, res);
maxsub_BST_helper(root->right, res);
}
