First it let M = 1, then r = 2, k = 2 and T = 1.  Next, M = 5, r = 2, k = 0, T = 3.  It will then change everything in [0, r] = [0, 2] to 5, or just change 1 to 5.

Can you tell me why the following gets Wrong Answer?

Let v[0..n-1] be the input sequence.

1. Let x = 0, cost = 0.

2. If x >= n, output cost and exit.

3. Let M be the minimum of v[x .. n-1].

4. Let r be the largest index in [x, n-1] such that v[r] <= M.

5. Let k be the number of indexes i in [x, r] with v[i] > v[r], and T be the number of indexes with v[i] <= v[r].

   Note that k + T = (r - x + 1).

6. If k > T, then let M be the next larger element in v[x .. n-1] and goto step 4.

   If k <= T, then change all values in v[x .. r] to M, record the cost.  Let x = r + 1 and goto step 2.

Thanks.

Can you tell me why the following gets Wrong Answer?

Let v[0..n-1] be the input sequence.

1. Let x = 0, cost = 0.

2. If x >= n, output cost and exit.

3. Let M be the minimum of v[x .. n-1].

4. Let r be the largest index in [x, n-1] such that v[r] <= M.

5. Let k be the number of indexes i in [x, r] with v[i] > v[r], and T be the number of indexes with v[i] <= v[r].

   Note that k + T = (r - x + 1).

6. If k > T, then let M be the next larger element in v[x .. n-1] and goto step 4.

   If k <= T, then change all values in v[x .. r] to M, record the cost.  Let x = r + 1 and goto step 2.

Thanks.

1.  For each contest (after actual contest), there is a page linked from the contest page to a tutorial / summary page.

2. There is a short match summary - I assume Mike or some other admins can write a little bit about it, then other statistical information can be automated.

3.  For each problem, there are tutorial(s), written by different authors / volunteers.  On the page itself only one is shown: the one with the most +, breaking tie by contest rating of author.  But, there is an option to see other tutorials (for the same problem, by a different author, sorted by +, breaking tie by rating of author).  A reader can then rate the tutorials with +/- (similar to #4 above).

4. An author can write at most one tutorial (post) for each problem/language combination.  He/She can, however, always edit and improve his current version, and previous version are also available to readers (like TopCoder Forum).  This is to prevent information overflow or having to look through chains of posts for information.

5. Tutorials for a different language (Russian, Chinese, etc.) can also be posted, in which case readers seeking help in a different language can get it.

6.  Readers can post comments for each tutorial, suggest improvement, but only the original author can make changes to it.

OK, let's see some use cases.

1. Code Forces Round 8 occurs.

2. I almost got problem D, but not yet, so I spent some more time playing with it.  Finally I solved it a few hours after contest and decided I want to write about I find out.

3. I write a tutorial about it.  At that time other people might have written tutorials for this problem, in which case I may decide not to spend extra effort.  Otherwise, what I wrote will be the first to appear for everyone else. (I can also choose to write short hints for different problems, and they will appear as tutorials written by me).

4.  Someone reads my tutorial, are unclear about certain explanation, found some typos.  He post a comment on this tutorial, and I got a notification.  

5.  I decided to make changes and improve my writeup for the problem.

6. Another reader reads my tutorial, and decides to write/translate it in his own language (Russian, Chinese, etc.)  Now, there are tutorials in multiple languages.  Since all posts and edits are time-stamped, the original write can always claim authorship (and the other becomes a translation).

7.  Anyone can write for any problem at any time after contest, things will increase and improve, and everything for one problem is located at one place.

It doesn't seem to be too much work on the infrastructure - just need a specific page for tutorials for each contest, and each piece of tutorial can be considered as similar to a post, with addition restriction that each author/problem/language combination only exists once, and with a different +/- system. 

As for reward, the number of +'s received on tutorials and number of first place tutorials can be a statistic on the author's page (may be even with ranking, not sure if too much ranking is a good thing).