///------------ Solution assuming no links to parent node ------------------------------------
public static List <TreeNode> FindPathBetweenTwoNodes(TreeNode root, TreeNode start, TreeNode end)
{
if (root == null || start == null || end == null)
{
return(null);
}
List <TreeNode> path = new List <TreeNode>();
if (start == end)
{
path.Add(start);
return(path);
}
// O(n) to get LCA
TreeNode commonAncestor = FindLowestCommonAncestor.GetCommonAncestor(root, start, end);
if (commonAncestor == null)
{
return(path); // start and end not not both under root
}
// build a child/parent map of the nodes below the common ancestor to make path building easier
Dictionary <TreeNode, TreeNode> childParentMap = new Dictionary <TreeNode, TreeNode>();
BuildChildParentMap(commonAncestor, null, childParentMap);
while (start != commonAncestor)
{
path.Add(start);
start = childParentMap[start];
}
path.Add(commonAncestor);
Stack <TreeNode> endPath = new Stack <TreeNode>();
while (end != commonAncestor)
{
endPath.Push(end);
end = childParentMap[end];
}
while (endPath.Count != 0)
{
path.Add(endPath.Pop());
}
return(path);
}
/// <summary>
/// interview questions for string problems
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
String[] words = { "abcde", "hello", "apple", "kite", "padle" };
foreach (string w in words)
{
Console.WriteLine(w + " : " + RandomStringProblem.isUniqueChars(w));
}
String s = "helloiloveyou";
Console.WriteLine(s + " -> " + RandomStringProblem.RemoveDuplicateCharacters(s));
Console.WriteLine(s + " -> " + RandomStringProblem.RemoveDuplicateCharacters(s.ToCharArray()));
Console.WriteLine("apple, papel : " + RandomStringProblem.anagram("apple", "papel"));
Console.WriteLine("carrot, tarroc : " + RandomStringProblem.anagram("carrot", "tarroc"));
Console.WriteLine("hello, llloh : " + RandomStringProblem.anagram("hello", "llloh"));
s = "A quick brown fox jumped over the log";
var sarr = s.ToArray();
var saar2 = s.ToArray();
RandomStringProblem.ReplaceFun(ref sarr, sarr.Length);
RandomStringProblem.ReplaceFun(ref saar2, sarr.Length);
Console.WriteLine(string.Concat(sarr));
Console.WriteLine(string.Concat(saar2));
Console.WriteLine("aabcccaa => " + RandomStringProblem.compress("aabcccaa"));
Console.WriteLine("aaaaaaab => " + RandomStringProblem.compress("aaaaaaab"));
Console.WriteLine("ababababab => " + RandomStringProblem.compress("ababababab"));
Console.WriteLine("avfffff => " + RandomStringProblem.compress("avfffff"));
FindFirstNonRepeatingChar.Test();
/// Linked List Problems
LinkedListNode head = AssortedMethods.randomLinkedList(10, 0, 3);
Console.WriteLine(head.printForward());
LinkedListProblems.deleteDups(head);
Console.WriteLine(head.printForward());
// wordbreak problems
TestWordBreak.Run();
//MedianOfMedians.TestMedianOfMedians();
LongestCommonSubsequence.Test();
SumOfMaxRunningSequence.Test();
TestRankNode.Test();
NextInorderSuccessor.Test();
CircularArrayTest.Test();
LongestPalindrome.Test();
IsomorphicStrings.Test();
FindMinAbsFrom2Arrays.Test();
ValidateIsBST.Test();
CoinPuzzle.Test();
BinarySearch.Test();
RansomNote.Test();
atoi.Test();
TrieTest.Test();
IsTreeBalanced.Test();
//TestProducerConsumer.Test();
ShuffleDeck.Test();
//QuickRankSearch.Test();
ParenthesisCombo.Test();
Permutations.Test();
Combinations.Test();
CompressString.Test();
BuildTreeFromMatrixInput.Test();
FindAllRepeatingSubstrings.Test();
PrintTreePaths.Test();
FindLowestCommonAncestor.Test();
PrintLevelsOfABinaryTree.Test();
FindPathBetween2NodesInTree.Test();
FindPathExistsInGraph.Test();
FindPathBetween2GraphNodes.Test();
// RealTimeCounterTest.Test();
DistanceBetweenWordsInASentence.Test();
SearchingForNextCharInSearch.Test();
HashMapTester.Test();
FindElementInRotatedArray.Test();
SubTrees.Test();
LongestCommonSubstring.Test();
LongestIncreasingSequenceQuestion.Test();
ConvertTreeIntoDoublyLinkedList.Test();
Count2sBetween0andN.Test();
TestSuffixTrees.Test();
TransformWordIntoOtherWord.Test();
IsNumberAPalindrome.Test();
ConvertNumberToPhrase.Test();
CountBinary1sInStream.Test();
ReverseBitsInUnsignedInt.Test();
ReverseLinkedList.Test();
DeleteDups.Test();
_3SUM.Test();
ArraySequencesThatAddUpToSum.Tests();
FindBSTNodesThatSumUpToValue.Test();
LengthOfLongestSubstringProblem.Test();
//BuildTreeFromInorderAndPreorderTraversal.Test();
ConvertTreeToDLL.Test();
FindMissingNumberInString.Test();
SortStackWithAnotherStack.Test();
QueueFrom2Stacks.Test();
Sort2Queues.Test();
ConvertRomanNumeralToInt.Test();
MergeAllLists.Test();
DivideWithoutSlash.Test();
//RegularExpression.Test();
IsNumberValid.Test();
Console.ReadKey();
}
