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 N1 lines contain N1 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
ramjeet saran:
20150822 14:25:59
not a binary tree, cost me 3 WA 

Khanh Ninh:
20150811 14:35:51
Dynamic Program + DFS , Advanced Solution. 

mohit:
20150804 20:54:44
DFS! diameter of a tree . http://www.geeksforgeeks.org/diameterofabinarytree/


sameer Hussain:
20150730 22:00:44
is it a binary tree or any random tree ??


Nitesh Tiwari:
20150725 23:25:25
Answer for the below test case is 6, spojtoolkit is showing 5, I got it accepted with 6.


Krzysztof Strojny:
20150722 11:03:16
This can be done in in one loop over vertices, take advantage that this is a tree, no need for BFS or DFS 

psionic:
20150712 23:55:11
DFS and DFS :D 

Ankur Arora:
20150712 21:57:35
kindly


santamaria:
20150703 17:20:14
Ohh yeah (BFS & BFS) :D 

Deeksha:
20150629 12:25:03
take 1 as start node.. Last edit: 20150629 20:39:20 
Added by:  ThanhVy Hua 
Date:  20070328 
Time limit:  0.5s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  Coauthor Amber 