TETRA - Sphere in a tetrahedron

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Of course a Sphere Online Judge System is bound to have some tasks about spheres. So here is one. Given the lengths of the edges of a tetrahedron calculate the radius of a sphere inscribed in that tetrahedron (i.e. a sphere tangent to all the faces).


Number N of test cases in a single line. ( N <= 30 ) Each of the next N lines consists of 6 integer numbers -- the lengths of the edges of a tetrahedron separated by single spaces. The edges are not longer than 1000 and for the tetrahedron WXYZ, the order of the edges is: WX, WY, WZ, XY, XZ, YZ.


N lines, each consisting of a real number given with four digits decimal precision equal to the radius of a sphere inscribed in the given tetrahedron.


1 1 1 1 1 1
1000 999 998 5 5 6


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tomasznowak: 2015-12-11 13:58:14

If you have good answers for the example and SPOJ gives "Wrong Answer", then you probably don't include the situation, where one (or more) of the edges is 0. If one is zero, therefore the radius is 0. Your program should also write 0 not as "0", but as "0.0000".

Kaushik Nath: 2015-01-18 07:38:31

Remember to take care of the decimal places
It should be only 4

Manu Agarwal: 2014-12-12 22:47:34

would anyone suggest me critical test cases . Getting WA even after right answer in sample test cases.

Minsuk Kim: 2014-11-29 05:13:03

weird - I'm getting correct answers for sample test cases but keep on getting wrong answer on submission too .... :(

aky: 2014-10-30 10:08:07

I am using C math library for sqrt etc and I am getting answer to the second one as 1.4186. Answer to first is correct! What's wrong with this approach?

hackab: 2014-06-11 21:50:41

#heron's formula .. :)

Deekshith Reddy Kallem: 2014-06-03 15:35:26

@sai spoorthy,1000 5 6 in the above problem do not form the sides of single face. 5 5 6 form the base triangle

sai spoorthy: 2014-05-22 18:26:04

i am getting answer for first one as 0.022680460581325723
in the second test case
for every tetrahedron there will be 4 triangles
but 1000 5 6 it cannot form triangle as sum of two sides is not greater than the other side
please help me!!!!!!!!!!!!!!!

Last edit: 2014-05-22 18:49:55
yaswanth: 2013-12-29 08:25:16

100th one :)

shikhar sharma: 2013-07-08 15:56:11

I am able to get the right answer for the sample test cases but still getting WA on submission.
Can someone please provide more testCases

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