Feb. 12, 2017
After the
contest, Julia likes to study a few of solutions in C#, Java and other
languages.
Code study of submissions
Have some
difficulty to understand the algorithm behind Index.Add method. Need to figure
out later. Add some test cases to C# code, debug and
understand the code one line by one line.
Study a few
things about C# coding style, pascal case, set, get, and then using GroupBy,
OrderBy, Aggregate, Stack, HashSet, Dictionary.
Second Study
C# code study II
C# code is here.
Third Study
Java implementation
Problems
The most readable code is here with trie implementation. Julia chose one solution from near 100 solutions, this one is easy to follow. Will rewrite the C# solution based on this Java implementation.
Actionable Items
1. Instead of studying other people's code, Julia decided to look into
test case 11 and figured out why her submission failed the test case.
2. Read editorial notes from hackerrank, understand the idea, google search them:
This problem can be solved using Trie and DP. Create a trie from the given set of strings. Find the prefix neighbor of each string. Now create a graph such that each string is a node and there exist a bidirectional edge between two nodes only if they are prefix neighbors. Now find the maximum weighted independent set.
Statistics
Difficulty: Medium
Time Complexity:
O(N*max_length_of_string)
Required
Knowledge: Trie
Publish Date: Mar
25 2016
Read the wiki article - Independent set ( graph theory)
GeeksforGeek
problem - Largest independent set problem.
3. Julia did not know the importance of problem solving in the contest and after the contest from Feb. 11 - 13, 2017. She tried to understand the other people's submission after the contest, and she had difficult time. She needs to understand the algorithm first, just follows the notes: find the maximum weighted independent set
4. Spent over 2 hours to rewrite the C# code, and post a question on stackexchange.com.
Problem solving - community help
Feb. 25, 2017 5:27pm
With the help from Peter Taylor through his code view, Julia learned so much about the problem solving skills. She answered code reviews one by one, and then felt so comfortable with the algorithm problem solving. The code review experience is top-rated performance.
With the help from Peter Taylor through his code view, Julia learned so much about the problem solving skills. She answered code reviews one by one, and then felt so comfortable with the algorithm problem solving. The code review experience is top-rated performance.
Share some comments here:
Advice #6, KISS, why? what is wrong to insert them all into one trie? This is a good question. I tried to use the above code, but use one trie instead of going through A to Z one by one, run the code on hackerrank, error from test case 6 to 19; And then, I tried not to sort by the length of string, error from test case 6 to 19. – Jianmin Chen Feb 15 at 5:06
Very good review, I did spend over a few hours in the contest and also a few hours after the contest. I like the last review "KISS, why?" most, remind me 5 whys for root cause analysis. Bravo! – Jianmin Chen Feb 15 at 5:11
Very good review, I did spend over a few hours in the contest and also a few hours after the contest. I like the last review "KISS, why?" most, remind me 5 whys for root cause analysis. Bravo! – Jianmin Chen Feb 15 at 5:11
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