编程介的小学生 2017-05-06 03:55 采纳率: 20.5%
浏览 809
已采纳

Crankshaft

One company develops a CAD system for crankshaft design. The crankshafts in question are combined of 0 < N <= 100 metal plates. All plates are made of the same alloy and have equal (small) thickness. Each plate has the shape of a polygon with 3 <= Vi <= 200 vertices. All plates in the crankshaft are parallel and firmly connected to each other. They are the only elements of the crankshaft.

Among other features, this CAD system should have a routine for determining the rotation axis of the crankshaft. More precisely, customers sometimes need to find a line, perpendicular to the plane of the crankshaft plates, rotation around which causes minimal vibration of the crankshaft. It is well known that such axis must pass through the mass center of the crankshaft.

The crankshaft design is stored as a set of vertex coordinates for each plate in some Cartesian coordinate system. The plane OXY of the system is parallel to the plates surfaces. All the coordinates are integer, -10^4 <= Xij, Yij <= 10^4, where 1 <= j <= Vi, 1 <= i <= N. The vertices are numbered clockwise (OX axis is directed rightwards, OY axis is directed upwards).

Your program should print the rotation axis coordinates (XR and YR). The correct answer should be given even for a partially designed crankshaft (consisting of two or more non-connected parts). You should suppose that these parts are firmly connected.

Input

The input consists of integer numbers, delimited by spaces and/or line feeds. The numbers are specified in the following order:

N
V1 X11 Y11 ... X1V1 Y1V1
...
VN XN1 YN1 ... XNVN YNVN

Output

The output should contain two real numbers: XR and YR. These values must be exact to four digits to the right of the decimal point.

This problem contains multiple test cases!

The first line of a multiple input is an integer N, then a blank line followed by N input blocks. Each input block is in the format indicated in the problem description. There is a blank line between input blocks.

The output format consists of N output blocks. There is a blank line between output blocks.

Sample Input

2

2
4 -1 -1 -1 1 1 1 1 -1
4 -1 -1 -1 0 0 0 0 -1

2
3 -2 -1 -2 1 -1 0
3 2 1 2 -1 1 0

Sample Output

-0.1 -0.1

0 0

  • 写回答

1条回答 默认 最新

  • threenewbee 2017-05-21 09:12
    关注
    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 Oracle中如何从clob类型截取特定字符串后面的字符
  • ¥15 想通过pywinauto自动电机应用程序按钮,但是找不到应用程序按钮信息
  • ¥15 如何在炒股软件中,爬到我想看的日k线
  • ¥15 seatunnel 怎么配置Elasticsearch
  • ¥15 PSCAD安装问题 ERROR: Visual Studio 2013, 2015, 2017 or 2019 is not found in the system.
  • ¥15 (标签-MATLAB|关键词-多址)
  • ¥15 关于#MATLAB#的问题,如何解决?(相关搜索:信噪比,系统容量)
  • ¥500 52810做蓝牙接受端
  • ¥15 基于PLC的三轴机械手程序
  • ¥15 多址通信方式的抗噪声性能和系统容量对比