GCJ1C09B - Center of Mass

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You are studying a swarm of N fireflies. Each firefly is moving in a straight line at a constant speed. You are standing at the center of the universe, at position (0, 0, 0). Each firefly has the same mass, and you want to know how close the center of the swarm will get to your location (the origin).

You know the position and velocity of each firefly at t = 0, and are only interested in t ≥ 0. The fireflies have constant velocity, and may pass freely through all of space, including each other and you. Let M(t) be the location of the center of mass of the N fireflies at time t. Let d(t) be the distance between your position and M(t) at time t. Find the minimum value of d(t), dmin, and the earliest time when d(t) = dmin, tmin.

Input

The first line of input contains a single integer T, the number of test cases. Each test case starts with a line that contains an integer N, the number of fireflies, followed by N lines of the form

x y z vx vy vz

Each of these lines describes one firefly: (x, y, z) is its initial position at time t = 0, and (vx, vy, vz) is its velocity.

Output

For each test case, output

Case #X: dmin tmin

where X is the test case number, starting from 1. Any answer with absolute or relative error of at most 10-6 will be accepted.

Limits

All the numbers in the input will be integers.
1 ≤ T ≤ 100
The values of x, y, z, vx, vy and vz will be between -5000 and 5000, inclusive.

Large dataset

3 ≤ N ≤ 500

Sample

Input
3
3
3 0 -4 0 0 3
-3 -2 -1 3 0 0
-3 -1 2 0 3 0
3
-5 0 0 1 0 0
-7 0 0 1 0 0
-6 3 0 1 0 0
4
1 2 3 1 2 3
3 2 1 3 2 1
1 0 0 0 0 -1
0 10 0 0 -10 -1

Output
Case #1: 0.00000000 1.00000000
Case #2: 1.00000000 6.00000000
Case #3: 3.36340601 1.00000000

Notes

Given N points (xi, yi, zi), their center of the mass is the point (xc, yc, zc), where:

xc = (x1 + x2 + ... + xN) / N
yc = (y1 + y2 + ... + yN) / N
zc = (z1 + z2 + ... + zN) / N

hide comments
Atul Kumar Verma: 2013-06-04 17:44:23

finally AC :)

piyush: 2013-06-04 07:05:01

please provide some more test cases, i am getting WA again and again

Himanshu Srivastava: 2013-06-01 01:18:50

so many WA's........dont write direct formulas :P

Last edit: 2013-06-01 01:19:11
(Tjandra Satria Gunawan)(曾毅昆): 2013-05-19 16:24:56

be careful for division with zero.. if you divide by zero using "double" type data, you don't get SIGFPE but the result is WA..

legrand: 2013-05-15 13:32:20

nice problem.

Last edit: 2013-05-15 14:14:50
Shafaet: 2013-05-07 14:37:39

Fixed now thanks. Spoj have a default blank input file, i forgot to remove it.

Jacob Plachta: 2013-05-07 14:37:08

It seems like the data wasn't correctly uploaded (or uploaded at all)... I'm unable to read the value "T".


Added by:Shafaet
Date:2013-05-07
Time limit:1s-20s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM64
Resource:Google Codejam 2009, Round 1C, Problem B