All Questions
13 questions
6
votes
2
answers
7k
views
Prefix search by trie tree
I'm working on the prefix search problem:
Given a set of words, for example words = ['a', 'apple', 'angle', 'angel', 'bat', 'bats'], for any given prefix, find ...
- 3,453
5
votes
1
answer
223
views
Using range minimal query for lowest common ancestor (LCA) -- part 2
Here is my code to use range minimal query to resolve the LCA problem. I applied comments from here.
Any advice on code bugs, performance improvement in terms of algorithm time complexity, code style ...
- 3,453
4
votes
1
answer
513
views
Using range minimal query for lowest common ancestor (LCA)
Here is my code to use range minimal query to resolve the LCA problem. Any advice on code bugs, performance improvement in terms of algorithm time complexity, code style are appreciated.
More ...
- 3,453
2
votes
0
answers
622
views
Vertical sum in a given binary tree
I'm working on this problem,
Problem statement,
Given a Binary Tree, find vertical sum of the nodes that are in same vertical line. Print all sums through different vertical lines.
Examples:
...
- 3,453
2
votes
2
answers
3k
views
Serialize and deserialize binary tree
Here is my code of serialize and de-serialize a binary tree, looking for advice. One issue in my mind which I cannot resolve is, I am using a global variable index, wondering if more elegant solutions ...
- 3,453
3
votes
1
answer
2k
views
Serialize and deserialize a tree
Suppose each node of a tree has maximum n children. I want to serialize and de-serialize for a tree. My current solution is doing pre-order traverse, and using <...
- 3,453
2
votes
1
answer
177
views
Find the shortest whole repetitive substring (part 2)
This is a continued improvement from discussion here (Find the shortest whole repetitive substring), since code has changed a lot dues to improvement, I post it here. Major smart ideas are from ...
- 3,453
7
votes
1
answer
3k
views
Trie Tree match string containing ? and *
Using Python 2.7 and here is my code which implement trie match for a whole word, and also support if the whole word contains ? (match any one character) or ...
- 3,453
1
vote
1
answer
12k
views
Print tree level by level including Empty node
Here is my code to print tree in a level by level way. It needs to print an empty node as well to keep tree structure like full binary tree for elegancy reasons.
I'm wondering if anything you think ...
- 3,453
5
votes
2
answers
554
views
Print tree in a zigzag manner
I want to print a tree in a zigzag manner level-by-level. I'm wondering if there are any logic issues in my code and any further performance improvement ideas by using a smarter algorithm ...
- 3,453
4
votes
1
answer
1k
views
Prove that the graph is a valid tree in Python
I recently solved this leetcode problem:
Given n nodes labeled from 0 to n - 1 and a list of undirected edges
(each edge is a pair of nodes), write a function to check whether
these edges make ...
- 623
2
votes
2
answers
2k
views
Count number of matching nodes in a Binary tree
Problem
Count the number of matching nodes in the subtree rooted at some node n.
Solution
...
- 5,127
4
votes
2
answers
7k
views
Binary tree data structure
I am learning about the binary tree data structure and implemented some basic functionality.
It was working great with module level functions until I realized that I need to keep track of the root ...
- 5,127