public void ValidateBSTAlgo_WhenTreeIsBST_ReturnsTrue()
{
// Arrange
var root = new BinaryTreeNode <int>(40);
var rootLeft = new BinaryTreeNode <int>(25);
var rootRight = new BinaryTreeNode <int>(40);
root.Left = rootLeft;
root.Right = rootRight;
var rootLeftLeft = new BinaryTreeNode <int>(24);
var rootLeftRight = new BinaryTreeNode <int>(39);
rootLeft.Left = rootLeftLeft;
rootLeft.Right = rootLeftRight;
var rootRightRight = new BinaryTreeNode <int>(100);
rootRight.Right = rootRightRight;
var rootRightRightLeft = new BinaryTreeNode <int>(60);
var rootRightRightRight = new BinaryTreeNode <int>(150);
rootRightRight.Left = rootRightRightLeft;
rootRightRight.Right = rootRightRightRight;
// Act
var actual = ValidateBST.ValidateBSTAlgo(root);
// Assert
actual.Should().BeTrue();
}
void InternalTest(int?[] tree, bool expected)
{
TreeNode root = TreeNode.Get(tree);
bool actual = ValidateBST.IsValidBST(root);
Assert.Equal <bool>(expected, actual);
}
public void ValidateBSTAlgo_WhenTreeIsNotBST_ReturnsFalse()
{
// Arrange
var root = new BinaryTreeNode <int>(40);
var rootLeft = new BinaryTreeNode <int>(40);
var rootRight = new BinaryTreeNode <int>(42);
root.Left = rootLeft;
root.Right = rootRight;
// Act
var actual = ValidateBST.ValidateBSTAlgo(root);
// Assert
actual.Should().BeFalse();
}
public static bool ValidateBst(ValidateBST tree, int minValue, int maxValue)
{
if (tree.value < minValue || tree.value >= maxValue)
{
return(false);
}
if (tree.left != null && !ValidateBst(tree.left, minValue, tree.value))
{
return(false);
}
if (tree.right != null && !ValidateBst(tree.right, tree.value, maxValue))
{
return(false);
}
return(true);
}
public void Validating_Should_AddNewNodeToTree_When_GivenAnInteger()
{
//arrange
var BST = new BST(10);
var sut = new[] { 5, 15, 10 };
foreach (var number in sut)
{
BST.Insert(number);
}
//act
bool results = ValidateBST.Validating(BST);
//assert
Assert.That(results, Is.False);
}
public void Insert_Should_AddNewNodeToTree_When_GivenAnInteger()
{
//arrange
var BST = new BST(10);
var sut = new[] { 15, 22, 13, 14, 5, 5, 2, 1 };
foreach (var number in sut)
{
BST.Insert(number);
}
//act
bool results = ValidateBST.ValidateInOrder(BST);
//assert
Assert.That(results, Is.True);
}
public void IsValid()
{
BinarySearchTree <int> bst = new BinarySearchTree <int>();
bst.AddChild(5);
bst.AddChild(3);
bst.AddChild(2);
bst.AddChild(6);
bst.AddChild(1);
bst.AddChild(4);
Assert.AreEqual(true, ValidateBST.IsValid(bst));
var newNode = new BinaryTreeNode <int>(-2);
newNode.Left = bst.root.Left;
newNode.Right = bst.root.Right;
bst.root = newNode;
Assert.AreEqual(false, ValidateBST.IsValid(bst));
}
// O(n) time | O(d) space
public static bool ValidateBst(ValidateBST tree)
{
return(ValidateBst(tree, Int32.MinValue, Int32.MaxValue));
}
public void ValidateBSTTest(TreeNode <int> root, bool expected)
{
bool result = ValidateBST.IsValidBST(root, int.MinValue, int.MaxValue);
Assert.Equal(expected, result);
}
