Check if a binary tree is.bad.txt

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

bool IsSubtreeLesser(Node *root, int value)
{
    if(root == NULL) return true;
    if(root->data <= value && IsSubtreeLesser(root->left, value) && IsSubtreeLesser(root->right, value))
    {
        return true;
    }
    else {
        return false;
    }
}
bool IsSubtreeGreater(Node *root, int value)
{
      if(root == NULL) return true;
    if(root->data <= value && IsSubtreeGreater(root->left, value) && IsSubtreeGreater(root->right, value))
    {
        return true;
    }
    else {
        return false;
    }
}
bool IsBinarySearchTree(Node *root)
{
    if(root == NULL) return true;
    if (IsSubtreeLesser(root->left, root->data) && IsSubtreeGreater(root->right, root->data) 
    && IsBinarySearchTree(root->left) && IsBinarySearchTree(root->right))
    {
        return true;
    }
    else {
      return false;
    }
    
}