COT  Count on a tree
You are given a tree with N nodes. The tree nodes are numbered from 1 to N. Each node has an integer weight.
We will ask you to perform the following operation:
 u v k : ask for the kth minimum weight on the path from node u to node v
Input
In the first line there are two integers N and M. (N, M <= 100000)
In the second line there are N integers. The ith integer denotes the weight of the ith node.
In the next N1 lines, each line contains two integers u v, which describes an edge (u, v).
In the next M lines, each line contains three integers u v k, which means an operation asking for the kth minimum weight on the path from node u to node v.
Output
For each operation, print its result.
Example
Input: 8 5 105 2 9 3 8 5 7 7 1 2 1 3 1 4 3 5 3 6 3 7 4 8
2 5 1
2 5 2
2 5 3
2 5 4
7 8 2
Output: 2
8
9
105
7
hide comments
sclchuck:
20190801 04:09:56
17 10


wzw1105:
20190501 08:27:06
the data u v in the input don't guarantee that u is the father of v 

zhanibek_02:
20190306 14:30:19
I have no idea about it, how can I solve it? 

cichipi_:
20181012 04:35:43
Not specifying w range is stupid :) Last edit: 20181012 13:35:56 

wolf3h2h2:
20180614 01:48:19
the abslute value of the weights can be > 1e9 Last edit: 20180614 02:24:21 

VilimL:
20180324 11:59:31
Please add new languages. 

thedark:
20170818 10:03:49
wtf n is not <= 1e5, wasted too much time, take limit of n 111111 to be on safe side..


darkghostnj:
20170726 22:05:16
the weights can be negative or bigger then 10^5 and that is why most people get WA on this problem 

ankit mathur:
20170717 16:45:20
I found this Tc as the trickest one.


kaushik_r:
20170606 14:56:41
If we list the elements in the path from node 7 to node 8 in the given example, we'll get [7, 9, 105, 3, 7] . The 3rd minimum number in the list is 7 or 9?

Added by:  Fotile 
Date:  20120214 
Time limit:  0.129s0.516s 
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