CF150E.Freezing with Style

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

This winter is so... well, you've got the idea :-) The Nvodsk road system can be represented as nn junctions connected with n1n-1 bidirectional roads so that there is a path between any two junctions. The organizers of some event want to choose a place to accommodate the participants (junction vv ), and the place to set up the contests (junction uu ). Besides, at the one hand, they want the participants to walk about the city and see the neighbourhood (that's why the distance between vv and uu should be no less than ll ). On the other hand, they don't want the participants to freeze (so the distance between vv and uu should be no more than rr ). Besides, for every street we know its beauty — some integer from 00 to 10910^{9} . Your task is to choose the path that fits in the length limits and has the largest average beauty. We shall define the average beauty as a median of sequence of the beauties of all roads along the path.

We can put it more formally like that: let there be a path with the length kk . Let aia_{i} be a non-decreasing sequence that contains exactly kk elements. Each number occurs there exactly the number of times a road with such beauty occurs along on path. We will represent the path median as number ak/2a_{⌊k/2⌋} , assuming that indexation starting from zero is used. x⌊x⌋ — is number хх , rounded down to the nearest integer.

For example, if a=0,5,12a={0,5,12} , then the median equals to 55 , and if a=0,5,7,12a={0,5,7,12} , then the median is number 77 .

It is guaranteed that there will be at least one path with the suitable quantity of roads.

输入格式

The first line contains three integers nn , ll , rr ( 1lr,n1051\le l\le r,n\le 10^{5} ).

Next n1n-1 lines contain descriptions of roads of the Nvodsk, each line contains three integers aia_{i} , bib_{i} , cic_{i} ( 1<=ai,bi<=n1<=a_{i},b_{i}<=n , 0<=ci<=1090<=c_{i}<=10^{9} , aibia_{i}≠b_{i} ) — junctions aia_{i} and bib_{i} are connected with a street whose beauty equals cic_{i} .

输出格式

Print two integers — numbers of the junctions, where to accommodate the participants and set up the contests, correspondingly. If there are multiple optimal variants, print any of them.

输入输出样例

  • 输入#1

    6 3 4
    1 2 1
    2 3 1
    3 4 1
    4 5 1
    5 6 1
    

    输出#1

    4 1
    
  • 输入#2

    6 3 4
    1 2 1
    2 3 1
    3 4 1
    4 5 2
    5 6 2
    

    输出#2

    6 3
    
  • 输入#3

    5 1 4
    1 2 1
    1 3 4
    3 4 7
    3 5 2
    

    输出#3

    4 3
    
  • 输入#4

    8 3 6
    1 2 9
    2 3 7
    3 4 7
    4 5 8
    5 8 2
    3 6 3
    2 7 4
    

    输出#4

    5 1
    

说明/提示

In the first sample all roads have the same beauty. That means that all paths of the positive length have the same median. Thus, any path with length from 33 to 44 , inclusive will be valid for us.

In the second sample the city looks like that: 1 - 2 - 3 - 4 - 5 - 6. Two last roads are more valuable and we should choose any path that contains both of them and has the suitable length. It is either the path between 22 and 66 or the path between 33 and 66 .

首页