Dec. 14, 2016
Problem statement:
https://www.hackerrank.com/contests/university-codesprint/challenges/kindergarten-adventures
Introduction:
Kindergarten adventure algorithm is the algorithm on HackerRank university codespring contest in November, 2016, and it is medium level difficulty. Julia spent over one hour to think about the algorithm in the contest, but she did not come out the idea using binary indexed tree or segment tree to solve it. After the contest, she likes to master the algorithm.
The Previous two blogs about the algorithm and solutions:
HackerRank - university codesprint - kindergarten adventures (after the contest)
http://juliachencoding.blogspot.ca/2016/11/hackerrank-university-codesprint_16.htmlHere is one C# solution she chose to study, here are her workout experience:
1. Put some analysis together,
2. Review code
3. Put together a new version
4. Share on stackexchange.com code review section.
https://gist.github.com/jianminchen/c3abd1d967c58132023b7235b69fdcdd
5. Post the question on the stackexchange.com as well.
Post the question on stackexchange.com code review:
http://codereview.stackexchange.com/questions/149613/hackerrank-university-codesprint-2016-kindergarten-adventures
6. StackExchange.come code review feedback:
put on hold as off-topic by Peilonrayz, forsvarir, BCdotWEB, Vogel612, t3chb0t 2 days ago
This question appears to be off-topic for this site. While what’s on- and off-topic is not always intuitive, you can learn more about it by reading the help center. The users who voted to close gave this specific reason:
- "Questions must involve real code that you own or maintain. Pseudocode, hypothetical code, or stub code should be replaced by a concrete implementation. Questions seeking an explanation of someone else's code are also off-topic." – Peilonrayz, forsvarir, BCdotWEB, Vogel612, t3chb0t
8. Julia knew that she has to work on one algorithm a time, and this algorithm takes time. She started her own practice, failed 3 times:
8.1. Wrote my own version of segment tree, first try: 2.18 (maximum score 30)
only pass 4 test cases.
https://gist.github.com/jianminchen/3fc3df275c903e94b780e1612f0171f6
8.2. Second practice, score 1.08 max-score: 30, pass test case 0 and 1.
https://gist.github.com/jianminchen/98f38cfb31bace070184b641c95d14b9
8.3. Third practice, score 0 max-score: 30, pass test case 0, 1
https://gist.github.com/jianminchen/1411dc08a2a2c059454f788add19bceb
It is a really good study case for understanding depth of problem solving. Timeout issue is critical, at the beginning of construction of segment tree, the time complexity should be O(n^2), not O(n), n is the people in the group, n < 100000.
Better score 0 to write your own code, comparing to copy other's code score 30. Do not underestimate your own practice, the mistakes made, time spent all counts to the good learning experience.
8. Go back to the study code C#:
And google and try to find some article to help.
The solution is classical, some one already did research how to store the value in segment tree most efficient way, almost O(n) to build up a segment tree.
Find the article using similar idea:
http://codeforces.com/blog/entry/18051?
Workout:
1. Show some graph on analysis of solution provided:
2. Get out from the first breakdown on stackexchange.com code review:
Have some sports therapy - 30 minutes
Watched the video of Genie Bourchard interview twice while she did some stretch in the living room, for a sports workout.
Eugenie Bouchard Live:
https://www.youtube.com/watch?v=w02BSPblBEs&t=320s
(Eugenia is a young player, 20 years old when she was interviewed. She talked about in the interview Nick is her great coach, when she was 12 years, she was taught how to deal with mental issues in sports - stay at moment on the court, no matter what happens )
Do not be lazy. Work hard, fail a few times and then get better. Julia, if you are in uncomfortable zone, that is the learning zone. Do not miss the learning opportunities.
Fail to post, the algorithm written is not mine. Need to come out my own solution first, and then, get code review. Tried various solutions, failed all times. Get to know the algorithm better.
And then, Julia gave her 30 minutes therapy, chose one of top tennis players to motivate herself. Work on algorithm is not easy, to be competitive, Julia has to learn what to work on. No shortcut. Hands on experience, stay at moment. When practice, make as many mistakes as you can. If you can afford the time.
The solution is classical, some one already did research how to store the value in segment tree most efficient way, almost O(n) to build up a segment tree.
Find the article using similar idea:
http://codeforces.com/blog/entry/18051?
Workout:
1. Show some graph on analysis of solution provided:
2. Get out from the first breakdown on stackexchange.com code review:
Have some sports therapy - 30 minutes
Watched the video of Genie Bourchard interview twice while she did some stretch in the living room, for a sports workout.
Eugenie Bouchard Live:
https://www.youtube.com/watch?v=w02BSPblBEs&t=320s
(Eugenia is a young player, 20 years old when she was interviewed. She talked about in the interview Nick is her great coach, when she was 12 years, she was taught how to deal with mental issues in sports - stay at moment on the court, no matter what happens )
Do not be lazy. Work hard, fail a few times and then get better. Julia, if you are in uncomfortable zone, that is the learning zone. Do not miss the learning opportunities.
Fail to post, the algorithm written is not mine. Need to come out my own solution first, and then, get code review. Tried various solutions, failed all times. Get to know the algorithm better.
And then, Julia gave her 30 minutes therapy, chose one of top tennis players to motivate herself. Work on algorithm is not easy, to be competitive, Julia has to learn what to work on. No shortcut. Hands on experience, stay at moment. When practice, make as many mistakes as you can. If you can afford the time.
No comments:
Post a Comment