QOJ.ac

QOJ

Time Limit: 10 s - 20 s Memory Limit: 1024 MB Total points: 27

#5967. Noisy Neighbors

Statistics

Problem

You are a landlord who owns a building that is an R x C grid of apartments; each apartment is a unit square cell with four walls. You want to rent out N of these apartments to tenants, with exactly one tenant per apartment, and leave the others empty. Unfortunately, all of your potential tenants are noisy, so whenever any two occupied apartments share a wall (and not just a corner), this will add one point of unhappiness to the building. For example, a 2x2 building in which every apartment is occupied has four walls that are shared by neighboring tenants, and so the building's unhappiness score is 4.

If you place your N tenants optimally, what is the minimum unhappiness value for your building?

Input

The first line of the input gives the number of test cases, T. T lines follow; each contains three space-separated integers: R, C, and N.

Output

For each test case, output one line containing "Case #x: y", where x is the test case number (starting from 1) and y is the minimum possible unhappiness for the building.

Limits

Memory limit: 1 GB.

1 ≤ T ≤ 1000.

0 ≤ NR*C.

Small dataset (12 Points)

Time limit: 240 10 seconds.

1 ≤ R*C ≤ 16.

Large dataset (15 Points)

Time limit: 480 20 seconds.

1 ≤ R*C ≤ 10000.

Sample

4
2 3 6
4 1 2
3 3 8
5 2 0
Case #1: 7
Case #2: 0
Case #3: 8
Case #4: 0

In Case #1, every room is occupied by a tenant and all seven internal walls have tenants on either side.

In Case #2, there are various ways to place the two tenants so that they do not share a wall. One is illustrated below.

In Case #3, the optimal strategy is to place the eight tenants in a ring, leaving the middle apartment unoccupied.

Here are illustrations of sample cases 1-3. Each red wall adds a point of unhappiness.

problem_5967_1.png
About Issues

We understand that our problem archive is not perfect. If you find any issues with the problem, including the statement, scoring configuration, time/memory limits, test cases, etc.

You may use this form to submit an issue regarding the problem. A problem moderator will review your issue and proceed it properly.

STOP! Before you submit an issue, please READ the following guidelines:

  1. This is not a place to publish a discussion, editorial, or requests to debug your code. Your issue will only be visible by you and problem moderators. Other users will not be able to view or reply your issues.
  2. Do not submit duplicated issues. If you have already submitted one, please wait for an moderator to review it. Submitting multiple issues will not speed up the review process and might cause your account to be banned.
  3. Issues must be filed in English or Chinese only.
  4. Be sure your issue is related to this problem. If you need to submit an issue regarding another problem, contest, category, etc., you should submit it to the corresponding page.

Active Issues 0

No issues in this category.

Closed/Resolved Issues 0

No issues in this category.