It is just a mining spanning tree ( 最小生成树 ) problem, what makes you a little difficult is that you are in a 3D space.
1012: A MST ProblemTime Limit: 1 Sec Memory Limit: 32 MB
Submit: 15 Solved: 11
The first line of the input contains the number of test cases in the file. And t he first line of each case
contains one integer numbers n(0<n<30) specifying the number of the point . The n next n line s, each line
contain s Three Integer Numbers xi,yi and zi, indicating the position of point i.
For each test case, output a line with the answer, which should accurately rounded to two decimals .
2 2 1 1 0 2 2 0 3 1 2 3 0 0 0 1 1 1