编程介的小学生 2017-09-10 15:26 采纳率: 20.5%
浏览 743
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 2017-09-27 14:11
    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 maple软件,用solve求反函数出现rootof,怎么办?
  • ¥50 汇编语言除法溢出问题
  • ¥15 Visual Studio问题
  • ¥15 state显示变量是字符串形式,但是仍然红色,无法引用,并显示类型不匹配
  • ¥20 求一个html代码,有偿
  • ¥100 关于使用MATLAB中copularnd函数的问题
  • ¥20 在虚拟机的pycharm上
  • ¥15 jupyterthemes 设置完毕后没有效果
  • ¥15 matlab图像高斯低通滤波
  • ¥15 针对曲面部件的制孔路径规划,大家有什么思路吗