public static void Process(TreeNode root)
{
Stack<TreeNode> stack = new Stack<TreeNode>();
TreeNode current = root;
TreeNode temp;
while (current != null || stack.Count > 0)
{
while (current != null)
{
stack.Push(current);
temp = current.Left;
current.Left = current.Right;
current.Right = temp;
current = current.Left;
}
if (stack.Count > 0)
{
current = stack.Pop().Right;
}
}
}
public void TestFirstIsNull()
{
TreeNode first = null;
TreeNode second = new TreeNode(1);
Assert.IsFalse(SubstructureInTree.Process(first, second));
}
public static void Process(TreeNode root, int sum)
{
if (root == null)
{
return;
}
}
public void TestInOrderTraverseOnlyRootTree()
{
TreeNode root = new TreeNode(1);
string expected = "1";
TreeNode.InOrderTraverseRecursively(root);
Assert.AreEqual(expected, TreeNode.Result);
TreeNode.InOrderTraverseIteratively(root);
Assert.AreEqual(expected, TreeNode.Result);
}
public static TreeNode ProcessIteratively(int[] preOrder, int[] inOrder)
{
if (preOrder == null ||
inOrder == null ||
preOrder.Length == 0 ||
inOrder.Length == 0 ||
preOrder.Length != inOrder.Length)
{
return null;
}
Dictionary<int, int> orders = new Dictionary<int, int>();
for(int i = 0; i < inOrder.Length; ++i)
{
orders.Add(inOrder[i], i);
}
TreeNode root = new TreeNode(preOrder[0]);
Stack<TreeNode> stack = new Stack<TreeNode>();
stack.Push(root);
TreeNode current = null;
TreeNode previous = null;
for (int i = 1; i < preOrder.Length; ++i)
{
current = new TreeNode(preOrder[i]);
if (!orders.ContainsKey(current.Value))
{
throw new ArgumentException(Constants.InvalidInput);
}
if (orders[current.Value] < orders[stack.Peek().Value])
{
stack.Peek().Left = current;
stack.Push(current);
}
else
{
while (stack.Count > 0 &&
orders[current.Value] > orders[stack.Peek().Value])
{
previous = stack.Pop();
}
previous.Right = current;
stack.Push(current);
}
}
return root;
}
public static TreeNode Clone(TreeNode root)
{
if (root == null)
{
return null;
}
TreeNode cloned = new TreeNode(root.Value);
cloned.Left = Clone(root.Left);
cloned.Right = Clone(root.Right);
return cloned;
}
public void TestNotSubTreeInNoRightChildTree()
{
TreeNode first = new TreeNode(8);
first.Left = new TreeNode(8);
first.Left.Left = new TreeNode(9);
first.Left.Left.Left = new TreeNode(3);
first.Left.Left.Left.Left = new TreeNode(5);
TreeNode second = new TreeNode(8);
second.Left = new TreeNode(9);
second.Left.Left = new TreeNode(2);
Assert.IsFalse(SubstructureInTree.Process(first, second));
}
public void TestCompleteTree()
{
TreeNode root = Helper.CreateTree(TreeType.CompleteTree);
TreeNode expected = new TreeNode(1);
expected.Left = new TreeNode(3);
expected.Left.Left = new TreeNode(7);
expected.Left.Right = new TreeNode(6);
expected.Right = new TreeNode(2);
expected.Right.Left = new TreeNode(5);
expected.Right.Right = new TreeNode(4);
MirrorOfBinaryTree.Process(root);
Assert.IsTrue(Helper.CompareBinaryTree(expected, root));
root = Helper.CreateTree(TreeType.CompleteTree);
MirrorOfBinaryTree.ProcessRecursively(root);
Assert.IsTrue(Helper.CompareBinaryTree(expected, root));
}
public static bool CompareBinaryTree(TreeNode first, TreeNode second)
{
if (first == second)
{
return true;
}
if (first == null || second == null)
{
return false;
}
if (!first.Equals(second))
{
return false;
}
return CompareBinaryTree(first.Left, second.Left) &&
CompareBinaryTree(first.Right, second.Right);
}
public static void InOrderTraverseIteratively(TreeNode root)
{
Stack<TreeNode> stack = new Stack<TreeNode>();
TreeNode current = root;
while (current != null || stack.Count > 0)
{
while (current != null)
{
stack.Push(current);
current = current.Left;
}
if (stack.Count > 0)
{
current = stack.Pop();
output.Append(current.Value);
current = current.Right;
}
}
}
public static void ProcessRecursively(TreeNode root)
{
if (root == null)
{
return;
}
TreeNode temp = root.Left;
root.Left = root.Right;
root.Right = temp;
if (root.Left != null)
{
ProcessRecursively(root.Left);
}
if (root.Right != null)
{
ProcessRecursively(root.Right);
}
}
public void TestLevelOrderTraverseOnlyRootTree()
{
TreeNode root = new TreeNode(1);
string expected = "1";
TreeNode.LevelOrderTraverse(root);
Assert.AreEqual(expected, TreeNode.Result);
}
public void TestOnlyOneNode()
{
TreeNode root = new TreeNode(1);
TreeNode expected = new TreeNode(1);
MirrorOfBinaryTree.Process(root);
Assert.IsTrue(Helper.CompareBinaryTree(expected, root));
root = new TreeNode(1);
MirrorOfBinaryTree.ProcessRecursively(root);
Assert.IsTrue(Helper.CompareBinaryTree(expected, root));
}
public static void InOrderTraverseRecursively(TreeNode root)
{
if (root != null)
{
InOrderTraverseRecursively(root.Left);
output.Append(root.Value);
InOrderTraverseRecursively(root.Right);
}
}
public static void PostOrderTraverseIteratively(TreeNode root)
{
Stack<TreeNode> stack = new Stack<TreeNode>();
TreeNode current = root;
TreeNode previous = null;
while (current != null || stack.Count > 0)
{
while (current != null)
{
stack.Push(current);
current = current.Left;
}
current = stack.Peek();
if (current.Right == null || current.Right == previous)
{
output.Append(current.Value);
previous = current;
stack.Pop();
current = null;
}
else
{
current = current.Right;
}
}
}
public void TestOnlyRootTree()
{
int[] preOrder = new int[] { 1 };
int[] inOrder = new int[] { 1 };
TreeNode expected = new TreeNode(1);
Assert.IsTrue(Helper.CompareBinaryTree(expected, ConstructBinaryTree.ProcessRecursively(preOrder, inOrder)));
Assert.IsTrue(Helper.CompareBinaryTree(expected, ConstructBinaryTree.ProcessIteratively(preOrder, inOrder)));
}
private static TreeNode ProcessCore(
int[] preOrder,
int startPreOrder,
int endPreOrder,
int[] inOrder,
int startInOrder,
int endInOrder)
{
TreeNode root = new TreeNode(preOrder[startPreOrder]);
if (startPreOrder == endPreOrder)
{
if (startInOrder == endInOrder &&
preOrder[startPreOrder] == inOrder[startInOrder])
{
return root;
}
else
{
throw new ArgumentException(Constants.InvalidInput);
}
}
int rootInOrder = startInOrder;
while (rootInOrder <= endInOrder && inOrder[rootInOrder] != root.Value)
{
++rootInOrder;
}
if (rootInOrder == endInOrder && inOrder[rootInOrder] != root.Value)
{
throw new ArgumentException(Constants.InvalidInput);
}
int leftLength = rootInOrder - startInOrder;
int leftPreOrderEnd = startPreOrder + leftLength;
if (leftLength > 0)
{
root.Left = ProcessCore(
preOrder,
startPreOrder + 1,
leftPreOrderEnd,
inOrder,
startInOrder,
rootInOrder - 1);
}
if (leftLength < endPreOrder - startPreOrder)
{
root.Right = ProcessCore(
preOrder,
leftPreOrderEnd + 1,
endPreOrder,
inOrder,
rootInOrder + 1,
endInOrder);
}
return root;
}
private static TreeNode CreateNoRightChildTree()
{
TreeNode root = new TreeNode(1);
root.Left = new TreeNode(2);
root.Left.Left = new TreeNode(3);
root.Left.Left.Left = new TreeNode(4);
root.Left.Left.Left.Left = new TreeNode(5);
return root;
}
public void TestWithSameTree()
{
TreeNode first = new TreeNode(8);
first.Left = new TreeNode(8);
first.Left.Left = new TreeNode(9);
first.Left.Right = new TreeNode(2);
first.Left.Right.Left = new TreeNode(4);
first.Left.Right.Right = new TreeNode(7);
first.Right = new TreeNode(7);
TreeNode second = Helper.Clone(first);
Assert.IsTrue(SubstructureInTree.Process(first, second));
}
public void TestSubTreeInNotCompleteTree()
{
TreeNode first = new TreeNode(8);
first.Left = new TreeNode(8);
first.Left.Left = new TreeNode(9);
first.Left.Right = new TreeNode(2);
first.Left.Right.Left = new TreeNode(4);
first.Left.Right.Right = new TreeNode(7);
first.Right = new TreeNode(7);
TreeNode second = new TreeNode(8);
second.Left = new TreeNode(9);
second.Right = new TreeNode(2);
Assert.IsTrue(SubstructureInTree.Process(first, second));
}
public void TestSubTreeInNoLeftChildTree()
{
TreeNode first = new TreeNode(8);
first.Right = new TreeNode(8);
first.Right.Right = new TreeNode(9);
first.Right.Right.Right = new TreeNode(2);
first.Right.Right.Right.Right = new TreeNode(5);
TreeNode second = new TreeNode(8);
second.Right = new TreeNode(9);
second.Right.Right = new TreeNode(2);
Assert.IsTrue(SubstructureInTree.Process(first, second));
}
public static void LevelOrderTraverse(TreeNode root)
{
if (root == null)
{
return;
}
Queue<TreeNode> queue = new Queue<TreeNode>();
queue.Enqueue(root);
TreeNode current;
while (queue.Count > 0)
{
current = queue.Dequeue();
output.Append(current.Value);
if (current.Left != null)
{
queue.Enqueue(current.Left);
}
if (current.Right != null)
{
queue.Enqueue(current.Right);
}
}
}
private static TreeNode CreateNotCompleteTree()
{
TreeNode root = new TreeNode(1);
root.Left = new TreeNode(2);
root.Left.Left = new TreeNode(4);
root.Left.Left.Right = new TreeNode(7);
root.Right = new TreeNode(3);
root.Right.Left = new TreeNode(5);
root.Right.Right = new TreeNode(6);
root.Right.Right.Left = new TreeNode(8);
return root;
}
public void TestOnlyOneNode()
{
TreeNode first = new TreeNode(1);
TreeNode second = new TreeNode(1);
Assert.IsTrue(SubstructureInTree.Process(first, second));
}
public IList <int> PreorderTraversal(TreeNode root)
{
return(PreorderTraversalIterative(root));
}
