public static int FindMaxWidth(NodeBinTree <int> tree)
{
if (tree == null)
{
return(0);
}
var q = new Queue <NodeBinTree <int> >();
q.Enqueue(tree);
var max = 1;
while (q.Count > 0)
{
var cnt = q.Count;
max = Math.Max(max, cnt);
for (int i = 0; i < cnt; i++)
{
var n = q.Dequeue();
if (n.Left != null)
{
q.Enqueue(n.Left);
}
if (n.Right != null)
{
q.Enqueue(n.Right);
}
}
}
return(max);
}
private static int CheckHeight(NodeBinTree <int> tree)
{
if (tree == null)
{
return(-1);
}
var leftHeight = CheckHeight(tree.Left);
if (leftHeight == int.MinValue)
{
return(int.MinValue);
}
var rightHeight = CheckHeight(tree.Right);
if (rightHeight == int.MinValue)
{
return(int.MinValue);
}
if (Math.Abs(leftHeight - rightHeight) > 1)
{
return(int.MinValue);
}
else
{
return(Math.Max(leftHeight, rightHeight) + 1);
}
}
public void TestFindMaxWidthOfTree()
{
//GIVEN a binary tree
// lets construct binary search tree - BST is used just to try, actually task is to find height of any binary tree
/*
* definition of BST (binary search tree)
* - The left subtree of a node contains only nodes with keys lesser than the node’s key.
* - The right subtree of a node contains only nodes with keys greater than the node’s key.
* - The left and right subtree each must also be a binary search tree.
*
* 5
* / \
* 3 8
* / \ / \
* 1 4 7 12
* / \ /
* -1 2 6
* /
* -3
* -3 + ()
*/
// 1st level
var tree = new NodeBinTree <int>(5);
// 2nd level
var left3 = new NodeBinTree <int>(3);
var right8 = new NodeBinTree <int>(8);
tree.Left = left3;
tree.Right = right8;
// 3rd level
var left1 = new NodeBinTree <int>(1);
var right4 = new NodeBinTree <int>(4);
var left7 = new NodeBinTree <int>(7);
var right12 = new NodeBinTree <int>(12);
left3.Left = left1;
left3.Right = right4;
right8.Left = left7;
right8.Right = right12;
// 4th level
var leftm1 = new NodeBinTree <int>(-1);
left1.Left = leftm1;
left1.Right = new NodeBinTree <int>(2);
right12.Left = new NodeBinTree <int>(6);
//5th level
leftm1.Left = new NodeBinTree <int>(-3);
//WHEN
var result = Solution.FindMaxWidth(tree);
//THEN
Assert.Equal(4, result);
}
public static Dictionary <int, int> CalculateVerticalSum(NodeBinTree <int> tree)
{
var verticalSums = new Dictionary <int, int>();
Calc(tree, 0, verticalSums);
return(verticalSums);
}
private static int GetHeight(NodeBinTree <int> root)
{
if (root != null)
{
return(1 + Math.Max(GetHeight(root.Left), GetHeight(root.Right)));
}
return(0);
}
public static void TestBreadthFirstTraversal()
{
//GIVEN
#region create tree
// 1st level
var tree = new NodeBinTree <int>(5);
// 2nd level
var left3 = new NodeBinTree <int>(3);
var right8 = new NodeBinTree <int>(8);
tree.Left = left3;
tree.Right = right8;
// 3rd level
var left1 = new NodeBinTree <int>(1);
var right4 = new NodeBinTree <int>(4);
var left7 = new NodeBinTree <int>(7);
var right12 = new NodeBinTree <int>(12);
left3.Left = left1;
left3.Right = right4;
right8.Left = left7;
right8.Right = right12;
// 4th level
var leftm1 = new NodeBinTree <int>(-1);
left1.Left = leftm1;
left1.Right = new NodeBinTree <int>(2);
//5th level
leftm1.Left = new NodeBinTree <int>(-3);
#endregion
//WHEN
var result = new List <int>();
var doSomething = new Action <int> ((p) => result.Add(p));
Solution <int> .BreadthFirstTraverse(tree, doSomething);
//THEN
var resultExpected = new List <int>()
{
5, 3, 8, 1, 4, 7, 12, -1, 2, -3
};
var isEqual = true;
for (int i = 0; i < resultExpected.Count; i++)
{
if (resultExpected[i] != result[i])
{
isEqual = false;
break;
}
}
Assert.True(isEqual);
}
// string will be returned as a representation of a file
// ------------- NON RECURSIVE solution, just for fun :) -----------------------
public static string SerializeBinaryTreeToFileNoRecursion(NodeBinTree <int> tree)
{
// travers with BFS and create an array as a storage (similar to min/max heap)
var index = 0;
var result = new string[100]; //TODO: create EnsureCapacity method
var stackOfNodes = new Stack <NodeBinTree <int> >();
var stackOfIndexes = new Stack <int>();
stackOfNodes.Push(tree);
stackOfIndexes.Push(index);
NodeBinTree <int> node;
while (stackOfNodes.Count > 0)
{
node = stackOfNodes.Pop();
index = stackOfIndexes.Pop();
if (node != null)
{
result[index] = node.Value.ToString();
// basically, here we flatten tree to an array, if node is placed in i-th place
// it's left and right node should be placed in i*2 + 1 and i*2 + 2 respectively
if (node.Left != null || node.Right != null)
{
stackOfNodes.Push(node.Right); stackOfNodes.Push(node.Left);
stackOfIndexes.Push(index * 2 + 2); stackOfIndexes.Push(index * 2 + 1); // similarity with minheap implementation
}
}
else
{
result[index] = "end";
}
}
var stringResult = new StringBuilder();
for (var i = 0; i < result.Length; i++)
{
if (result[i] == "end")
{
break;
}
if (i > 0)
{
stringResult.Append(',');
}
stringResult.Append(result[i] != null ? result[i].ToString() : "e");
}
return(stringResult.ToString());
}
public static bool IsTreeBalanced(NodeBinTree <int> tree)
{
var height = CheckHeight(tree);
if (height == int.MinValue)
{
return(false);
}
return(true);
}
public static Node <int> Execute(NodeBinTree <int> tree)
{
var start = new Node <int>()
{
Value = tree.Value
};
Flatten(tree, start);
return(start);
}
public static List <Node <T> > CreateListOfDepths(NodeBinTree <T> tree)
{
var listOfDepths = new List <Node <T> >();
listOfDepths.Add(new Node <T>(tree.Value)); // added to index 0 - first level
AddToLevel(listOfDepths, tree.Left, 1);
AddToLevel(listOfDepths, tree.Right, 1);
return(listOfDepths);
}
public void TestValidBST()
{
//GIVEN
/*
* 5
* / \
* 3 8
* / \ / \
* 1 4 7 12
* / \
* -1 2
* /
* -3
*/
// 1st level
var tree = new NodeBinTree <int>(5);
// 2nd level
var left3 = new NodeBinTree <int>(3);
var right8 = new NodeBinTree <int>(8);
tree.Left = left3;
tree.Right = right8;
// 3rd level
var left1 = new NodeBinTree <int>(1);
var right4 = new NodeBinTree <int>(4);
var left7 = new NodeBinTree <int>(7);
var right12 = new NodeBinTree <int>(12);
left3.Left = left1;
left3.Right = right4;
right8.Left = left7;
right8.Right = right12;
// 4th level
var leftm1 = new NodeBinTree <int>(-1);
left1.Left = leftm1;
left1.Right = new NodeBinTree <int>(2);
//5th level
// by adding this node we make tree unbalanced
leftm1.Left = new NodeBinTree <int>(-3);
//WHEN
var result = Solution.IsValidBST(tree);
//THEN
Assert.True(result);
}
private static int Height(NodeBinTree <int> node)
{
if (node == null)
{
return(0);
}
var leftHeight = Height(node.Left);
var rightHeigt = Height(node.Right);
return(1 + Math.Max(leftHeight, rightHeigt));
}
public static void InOrderTraversal(NodeBinTree <T> node, Action <NodeBinTree <T> > visit = null)
{
if (node != null)
{
InOrderTraversal(node.Left, visit);
if (visit != null)
{
visit(node);
}
InOrderTraversal(node.Right, visit);
}
}
private static string Serialize(NodeBinTree <int> node)
{
if (node == null)
{
return("e,");
}
//preorder traversal
var value = node.Value;
var left = Serialize(node.Left);
var right = Serialize(node.Right);
return(value + "," + left + right);
}
private static NodeBinTree <int> GetBSTMinHeight(int[] array, int start, int end)
{
if (end < start)
{
return(null);
}
var mid = (start + end) / 2;
NodeBinTree <int> root = new NodeBinTree <int>(array[mid]);
root.Left = GetBSTMinHeight(array, start, mid - 1);
root.Right = GetBSTMinHeight(array, mid + 1, end);
return(root);
}
private static void GetNthElement(NodeBinTree <int> node, int level, ref int nth)
{
if (node == null)
{
return;
}
if (level == 0)
{
nth = node.Value;
}
else
{
GetNthElement(node.Left, level - 1, ref nth);
GetNthElement(node.Right, level - 1, ref nth);
}
}
private static NodeBinTree <int> Deserialize(Queue <string> q)
{
var value = q.Dequeue();
if (string.IsNullOrEmpty(value) || value == "e")
{
return(null);
}
//preorder traversal
var node = new NodeBinTree <int>(int.Parse(value));
node.Left = Deserialize(q);
node.Right = Deserialize(q);
return(node);
}
private static void Diametar(NodeBinTree <int> node, ref int maxd, ref NodeBinTree <int> maxDiametarNode)
{
if (node == null)
{
return;
}
var d = 1 + Height(node.Left) + Height(node.Right);
if (d > maxd)
{
maxd = d;
maxDiametarNode = node;
}
Diametar(node.Left, ref maxd, ref maxDiametarNode);
Diametar(node.Right, ref maxd, ref maxDiametarNode);
}
public static bool IsValidBST(NodeBinTree <int> tree)
{
//version 1
//InOrder traverse of BST should return numbers in ascending sorted order
var prev = int.MinValue;
Func <NodeBinTree <int>, bool> compare = (n) =>
{
if (prev > n.Value)
{
return(false);
}
prev = n.Value;
return(true);
};
return(IsValid(tree, compare));
}
public static int FindHeightBinaryTree(NodeBinTree <T> tree)
{
if (tree == null)
{
throw new ArgumentNullException("tree root cannot be null");
}
var leftHeight = GetHeight(tree.Left);
var rightHeight = GetHeight(tree.Right);
if (leftHeight > rightHeight)
{
return(1 + leftHeight);
}
else
{
return(1 + rightHeight);
}
}
private static int GetHeight(NodeBinTree <T> node)
{
if (node == null)
{
return(0);
}
var leftHeight = GetHeight(node.Left);
var rightHeight = GetHeight(node.Right);
if (leftHeight > rightHeight)
{
return(1 + leftHeight);
}
else
{
return(1 + rightHeight);
}
}
public static int Execute(NodeBinTree <int> tree)
{
// find max left height + max right height + 1
var max = 0;
var maxDiametarNode = tree;
Diametar(tree, ref max, ref maxDiametarNode);
var leftH = Height(maxDiametarNode.Left);
var rightH = Height(maxDiametarNode.Right);
int a = int.MinValue;
int b = int.MinValue;
GetNthElement(maxDiametarNode.Left, leftH - 1, ref a);
GetNthElement(maxDiametarNode.Right, rightH - 1, ref b);
return(Math.Abs(a - b));
}
private static void Calc(NodeBinTree <int> node, int hLevel, Dictionary <int, int> verticalSums) // hLeve stands for horizontal level
{
if (node == null)
{
return;
}
if (!verticalSums.ContainsKey(hLevel))
{
verticalSums[hLevel] = node.Value;
}
else
{
verticalSums[hLevel] += node.Value;
}
Calc(node.Left, hLevel - 1, verticalSums);
Calc(node.Right, hLevel + 1, verticalSums);
}
public void TestBinaryTreeToLinkedList(NodeBinTree <int> tree, Node <int> resultExpected)
{
// arrange, create test bin tree
// act
var result = Solution.Execute(tree);
// assert
var next = result;
var nextExpected = resultExpected;
while (next != null)
{
Assert.Equal(nextExpected.Value, next.Value);
next = next.Next;
nextExpected = nextExpected.Next;
}
}
private static void AddToLevel(List <Node <T> > listOfDepths, NodeBinTree <T> node, int addToLevel)
{
if (node == null)
{
return;
}
var newNode = new Node <T>(node.Value);
if (listOfDepths.Count - 1 >= addToLevel)
{
newNode.Next = listOfDepths[addToLevel];
listOfDepths[addToLevel] = newNode;
}
else
{
listOfDepths.Add(newNode);
}
AddToLevel(listOfDepths, node.Left, addToLevel + 1);
AddToLevel(listOfDepths, node.Right, addToLevel + 1);
}
public void TestCounterClockwiseBinTree()
{
// arrange
// create test tree
// 0 raw
var tree = new NodeBinTree <int>(1);
// 1st raw
tree.Left = new NodeBinTree <int>(2);
tree.Right = new NodeBinTree <int>(3);
// 2nd raw
tree.Right.Left = new NodeBinTree <int>(5);
tree.Right.Right = new NodeBinTree <int>(6);
tree.Left.Left = new NodeBinTree <int>(4);
// 3rd raw
tree.Left.Left.Left = new NodeBinTree <int>(7);
tree.Left.Left.Right = new NodeBinTree <int>(8);
tree.Right.Left.Left = new NodeBinTree <int>(9);
tree.Right.Right.Left = new NodeBinTree <int>(10);
tree.Right.Right.Right = new NodeBinTree <int>(11);
var resultExpected = new List <int>()
{
1, 7, 8, 9, 10, 11, 3, 2, 4, 5, 6
};
// act
var result = Solution.Execute(tree);
// assert
Assert.Equal(resultExpected.Count, result.Count);
for (int i = 0; i < result.Count; i++)
{
Assert.Equal(resultExpected[i], result[i]);
}
}
private static Node <int> Flatten(NodeBinTree <int> node, Node <int> parentNode)
{
var lastNode = parentNode;
if (node.Left != null)
{
parentNode.Next = new Node <int>()
{
Value = node.Left.Value
};
lastNode = Flatten(node.Left, parentNode.Next);
}
if (node.Right != null)
{
lastNode.Next = new Node <int>()
{
Value = node.Right.Value
};
lastNode = Flatten(node.Right, lastNode.Next);
}
return(lastNode);
}
private static void AddLevel(NodeBinTree <int> root, int level, bool isRevert, List <int> ret)
{
if (root == null)
{
return;
}
if (level == 0)
{
ret.Add(root.Value);
}
if (level > 0)
{
if (isRevert)
{
AddLevel(root.Right, level - 1, isRevert, ret);
AddLevel(root.Left, level - 1, isRevert, ret);
}
else
{
AddLevel(root.Left, level - 1, isRevert, ret);
AddLevel(root.Right, level - 1, isRevert, ret);
}
}
}
private static bool IsValid(NodeBinTree <int> root, Func <NodeBinTree <int>, bool> compare)
{
if (root == null)
{
return(true);
}
if (!IsValid(root.Left, compare))
{
return(false);
}
if (!compare(root))
{
return(false);
}
if (!IsValid(root.Right, compare))
{
return(false);
}
return(true);
}
public void TestDiffTwoLongestRelatedNodesInBinTree()
{
// arrange
var tree = new NodeBinTree <int>(1);
tree.Left = new NodeBinTree <int>(2);
tree.Right = new NodeBinTree <int>(3);
tree.Left.Left = new NodeBinTree <int>(4);
tree.Left.Right = new NodeBinTree <int>(5);
tree.Left.Left.Right = new NodeBinTree <int>(8);
tree.Left.Right.Left = new NodeBinTree <int>(6);
tree.Left.Right.Right = new NodeBinTree <int>(7);
tree.Left.Right.Right.Right = new NodeBinTree <int>(10);
tree.Left.Left.Right.Left = new NodeBinTree <int>(9);
// act
var result = Solution.Execute(tree);
// assert
Assert.Equal(1, result);
}