Comments on: Tutorial: Johnny and the Beanstalk (A2 Review) http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/ Practice. Compete. Discuss. Sun, 12 Feb 2012 15:11:00 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: EkramPrashanta http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-93 EkramPrashanta Thu, 08 Oct 2009 06:36:21 +0000 http://blog.codechef.com/?p=121#comment-93 In ffice right now will go through this latter.<br><br>respect<br>james<br>______________________________________________<br><a href="http://www.oforu.com" target="_blank" rel="nofollow">Buy Aion Kinah</a> | <a href="http://www.eing.com" target="_blank" rel="nofollow">Cheap Aion kinah</a> In ffice right now will go through this latter.

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]]> By: EkramPrashanta http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-1571 EkramPrashanta Thu, 08 Oct 2009 06:36:00 +0000 http://blog.codechef.com/?p=121#comment-1571 In ffice right now will go through this latter.respectjames______________________________________________<a href="http://www.oforu.com" rel="nofollow">Buy Aion Kinah</a> | <a href="http://www.eing.com" rel="nofollow">Cheap Aion kinah</a> In ffice right now will go through this latter.respectjames______________________________________________Buy Aion Kinah | Cheap Aion kinah

]]> By: Deepak S Patwardhan http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-92 Deepak S Patwardhan Fri, 25 Sep 2009 13:26:03 +0000 http://blog.codechef.com/?p=121#comment-92 I like the problem and let me rephrase it from a data structures point of view (for what its worth).<br><br>Problem : You are given the height of a full binary tree, and a sequence of numbers, which is claimed to be the number of leaves at each level, starting from the top. You have to verify that claim is theoretically possible.<br><br>Approach 1: Grow a tree.<br>Start with a single node, and grow the tree in order to satisfy the alleged number of leaves at each level, starting at top. If the claim is wrong, you'll either be unable to satisfy at a certain level (because the claim is too big), or will be left with extra leaves at the end. (claim was too small)<br><br>Approach 2: Prune a tree. (not eco-friendly)<br>Given the number of leaves at the bottom of the tree, cut them to increase the number of leaves at the previous level and decrease the height of the tree. Iterate. If the claim is wrong, you'll either reach a level with odd number of leaves or end up with a zero height tree with more than one node.<br><br>**<br><br>Its interesting to see the the variation in runtimes, within the same language, of course. With my best efforts, I couldn't bring my runtime (14) anywhere close to the best, which is just less than 0.4.<br><br>If I/O is the reason behind it, I guess this is my first hand experience of how slow I/O can be, if you don't take care of it. I like the problem and let me rephrase it from a data structures point of view (for what its worth).

Problem : You are given the height of a full binary tree, and a sequence of numbers, which is claimed to be the number of leaves at each level, starting from the top. You have to verify that claim is theoretically possible.

Approach 1: Grow a tree.
Start with a single node, and grow the tree in order to satisfy the alleged number of leaves at each level, starting at top. If the claim is wrong, you'll either be unable to satisfy at a certain level (because the claim is too big), or will be left with extra leaves at the end. (claim was too small)

Approach 2: Prune a tree. (not eco-friendly)
Given the number of leaves at the bottom of the tree, cut them to increase the number of leaves at the previous level and decrease the height of the tree. Iterate. If the claim is wrong, you'll either reach a level with odd number of leaves or end up with a zero height tree with more than one node.

**

Its interesting to see the the variation in runtimes, within the same language, of course. With my best efforts, I couldn't bring my runtime (14) anywhere close to the best, which is just less than 0.4.

If I/O is the reason behind it, I guess this is my first hand experience of how slow I/O can be, if you don't take care of it.

]]> By: Deepak S Patwardhan http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-1570 Deepak S Patwardhan Fri, 25 Sep 2009 13:26:00 +0000 http://blog.codechef.com/?p=121#comment-1570 I like the problem and let me rephrase it from a data structures point of view (for what its worth).Problem : You are given the height of a full binary tree, and a sequence of numbers, which is claimed to be the number of leaves at each level, starting from the top. You have to verify that claim is theoretically possible.Approach 1: Grow a tree.Start with a single node, and grow the tree in order to satisfy the alleged number of leaves at each level, starting at top. If the claim is wrong, you'll either be unable to satisfy at a certain level (because the claim is too big), or will be left with extra leaves at the end. (claim was too small)Approach 2: Prune a tree. (not eco-friendly)Given the number of leaves at the bottom of the tree, cut them to increase the number of leaves at the previous level and decrease the height of the tree. Iterate. If the claim is wrong, you'll either reach a level with odd number of leaves or end up with a zero height tree with more than one node.**Its interesting to see the the variation in runtimes, within the same language, of course. With my best efforts, I couldn't bring my runtime (14) anywhere close to the best, which is just less than 0.4.If I/O is the reason behind it, I guess this is my first hand experience of how slow I/O can be, if you don't take care of it. I like the problem and let me rephrase it from a data structures point of view (for what its worth).Problem : You are given the height of a full binary tree, and a sequence of numbers, which is claimed to be the number of leaves at each level, starting from the top. You have to verify that claim is theoretically possible.Approach 1: Grow a tree.Start with a single node, and grow the tree in order to satisfy the alleged number of leaves at each level, starting at top. If the claim is wrong, you'll either be unable to satisfy at a certain level (because the claim is too big), or will be left with extra leaves at the end. (claim was too small)Approach 2: Prune a tree. (not eco-friendly)Given the number of leaves at the bottom of the tree, cut them to increase the number of leaves at the previous level and decrease the height of the tree. Iterate. If the claim is wrong, you'll either reach a level with odd number of leaves or end up with a zero height tree with more than one node.**Its interesting to see the the variation in runtimes, within the same language, of course. With my best efforts, I couldn't bring my runtime (14) anywhere close to the best, which is just less than 0.4.If I/O is the reason behind it, I guess this is my first hand experience of how slow I/O can be, if you don't take care of it.

]]> By: JensenDP http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-91 JensenDP Wed, 08 Jul 2009 16:48:22 +0000 http://blog.codechef.com/?p=121#comment-91 zootzoot, I don't quite understand what you mean by an "input that has the highest level of a 0". Can you give an example? zootzoot, I don’t quite understand what you mean by an “input that has the highest level of a 0″. Can you give an example?

]]> By: JensenDP http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-1569 JensenDP Wed, 08 Jul 2009 16:48:00 +0000 http://blog.codechef.com/?p=121#comment-1569 zootzoot, I don't quite understand what you mean by an "input that has the highest level of a 0". Can you give an example? zootzoot, I don’t quite understand what you mean by an “input that has the highest level of a 0″. Can you give an example?

]]> By: zootzoot http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-90 zootzoot Sat, 27 Jun 2009 20:22:03 +0000 http://blog.codechef.com/?p=121#comment-90 PS. You have to exclude any input that has the highest level of a 0. PS. You have to exclude any input that has the highest level of a 0.

]]> By: zootzoot http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-1568 zootzoot Sat, 27 Jun 2009 20:22:00 +0000 http://blog.codechef.com/?p=121#comment-1568 PS. You have to exclude any input that has the highest level of a 0. PS. You have to exclude any input that has the highest level of a 0.

]]> By: zootzoot http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-89 zootzoot Sat, 27 Jun 2009 20:16:50 +0000 http://blog.codechef.com/?p=121#comment-89 There is also a mathematical way of solving this problem. If you have input with 3 levels (example 0 1 2): level1 * 2^2 + level2 * 2^1 + level3 * 2^0 = 2^(num of levels - 1) The same principle can be applied to any number of levels. I have tested my solution for the Beanstalk problem against test data validated using the above formula, but it still says my answer is wrong? There is also a mathematical way of solving this problem. If you have input with 3 levels (example 0 1 2):

level1 * 2^2 +
level2 * 2^1 +
level3 * 2^0
=
2^(num of levels – 1)

The same principle can be applied to any number of levels.

I have tested my solution for the Beanstalk problem against test data validated using the above formula, but it still says my answer is wrong?

]]> By: zootzoot http://blog.codechef.com/2009/03/17/johnny-and-the-beanstalk/#comment-1567 zootzoot Sat, 27 Jun 2009 20:16:00 +0000 http://blog.codechef.com/?p=121#comment-1567 There is also a mathematical way of solving this problem. If you have input with 3 levels (example 0 1 2): level1 * 2^2 + level2 * 2^1 + level3 * 2^0 = 2^(num of levels - 1) The same principle can be applied to any number of levels. I have tested my solution for the Beanstalk problem against test data validated using the above formula, but it still says my answer is wrong? There is also a mathematical way of solving this problem. If you have input with 3 levels (example 0 1 2):

level1 * 2^2 +
level2 * 2^1 +
level3 * 2^0
=
2^(num of levels – 1)

The same principle can be applied to any number of levels.

I have tested my solution for the Beanstalk problem against test data validated using the above formula, but it still says my answer is wrong?

]]>