PT07Z - Longest path in a tree


You are given an unweighted, undirected tree. Write a program to output the length of the longest path (from one node to another) in that tree. The length of a path in this case is number of edges we traverse from source to destination.

Input

The first line of the input file contains one integer N --- number of nodes in the tree (0 < N <= 10000). Next N-1 lines contain N-1 edges of that tree --- Each line contains a pair (u, v) means there is an edge between node u and node v (1 <= u, v <= N).

Output

Print the length of the longest path on one line.

Example

Input:
3
1 2
2 3

Output:
2

hide comments
xopxop1: 2017-08-18 13:20:05

Solution to this and many other tasks are here http://xoptutorials.com/index.php/category/spoj/

sharma96: 2017-08-15 22:05:04

Can anyone please tell how to handle this test case:
3
1 2
1 3
2 4

The question specifies N-1 lines will be input,but in this test case there are N lines.

Last edit: 2017-08-15 22:07:57
Shantanu Banerjee: 2017-08-08 08:44:15

Simple Double DFS!

sunidhi: 2017-08-04 06:17:12

@anuraag19 spoj won't allow us to see your solution.use some other platform to share your code.

anuraag19: 2017-08-02 18:51:15

does anybody know why i am getting runtime error?
http://www.spoj.com/status/PT07Z,anuraag19/

Last edit: 2017-08-02 18:52:12
karthik_vg: 2017-07-18 13:55:21

dfs + memorization ;)

sagnik_66: 2017-07-05 10:48:57

Solved using single DFS, this helped : https://cptalks.quora.com/Diameter-of-a-Tree

phben: 2017-07-04 03:24:22

@prashant2018 How to see the test cases? Aren't they hidden?

ashwani0605: 2017-06-21 06:52:03

Some of the answer in SPOJ toolkit are wrong, so verify on your own

sandeep_4141: 2017-06-14 10:27:13

dfs


Added by:Thanh-Vy Hua
Date:2007-03-28
Time limit:0.181s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Co-author Amber