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 N-1 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

Added by:Fotile
Date:2012-02-14
Time limit:1s
Source limit:6000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ASM32-GCC ASM64 MAWK BC C-CLANG NCSHARP CPP14 CPP14-CLANG COBOL COFFEE D-CLANG D-DMD DART ELIXIR FANTOM FORTH GOSU GRV JS-MONKEY JULIA KTLN NIM NODEJS OBJC OBJC-CLANG OCT PICO PROLOG PYPY PYPY3 PY_NBC R RACKET RUST CHICKEN SQLITE SWIFT UNLAMBDA VB.NET
Resource:Just for fun...

hide comments
2019-03-06 14:30:19
I have no idea about it, how can I solve it?
2018-10-12 04:35:43
Not specifying w range is stupid :)

Last edit: 2018-10-12 13:35:56
2018-06-14 01:48:19
the abslute value of the weights can be > 1e9

Last edit: 2018-06-14 02:24:21
2018-03-24 11:59:31 VilimL
Please add new languages.
2017-08-18 10:03:49
wtf n is not <= 1e5, wasted too much time, take limit of n 111111 to be on safe side..


Last edit: 2017-08-18 10:04:18
2017-07-26 22:05:16
the weights can be negative or bigger then 10^5 and that is why most people get WA on this problem
2017-07-17 16:45:20 ankit mathur
I found this Tc as the trickest one.
7 7
4 10 2 2 5 5 4
1 2
2 3
3 4
4 5
5 6
6 7
1 7 1
1 7 2
1 7 3
1 7 4
1 7 5
1 7 6
1 7 7
Output:
2
2
4
4
5
5
10

Also weight of nodes could be -ve also. and weight of nodes is greater than 10^5.
2017-06-06 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?
EDIT: Okay its 7

Last edit: 2017-06-06 15:50:58
2017-05-23 15:24:46 californiagurl
I am getting WA. Is there any tricky test case? I used persistent segment tree, and even used long long.

Last edit: 2017-05-23 15:27:13
2016-10-26 23:25:44 Ravi kumar
n & m are greater than 10^5. cost me few wa :(
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