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
snehil10111995: 2015-10-17 13:41:56

@Mohit, your given graph is not a connected tree. Rather it is a forest with two trees.

Mohit Rathore: 2015-10-17 07:13:43

Am I misunderstanding the question? For this test case answer should be 3 (4->5->6->7)
7
1 2
2 3
4 5
5 6
6 7
5 7

but one of the accepted solution answered it as 2.

kejriwal: 2015-10-12 10:16:36

nice one !

[Mayank Pratap]: 2015-10-10 17:03:08

this time using DFS :)

f3l1pe: 2015-10-05 02:58:52

Si hay alguno de la UTN lo puede resolver, que me mande un mail a lopezfelipeutn@gmail.com con su código; Estoy buscando miembros para competir

sneh sajal: 2015-09-21 15:13:16

normal recurrsion to get max level!! or you can say bfs or dfs :)

:.Mohib.:: 2015-09-17 17:00:47

Nice...!!

[Mayank Pratap]: 2015-09-16 15:54:02

Good prob to increase confidence in tree.. :)

Guilherme Sena: 2015-09-08 05:36:36

@Nitesh Tiwari : That is not a tree. (1,2,3,11) is a cycle since edges are undirected.

Pratik: 2015-08-31 12:08:54

Very good problem with a simple solution


Added by:Thanh-Vy Hua
Date:2007-03-28
Time limit:0.5s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: ERL JS-RHINO NODEJS PERL6 VB.NET
Resource:Co-author Amber