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
arpitscoding: 2016-09-26 17:14:54

f you! 5th test case.

rkasat: 2016-09-26 00:06:57

one bfs to find the farthest node. second bfs to find the longest path. AC in one go!

Kuldeep Fouzdar: 2016-09-25 19:02:27

CLRS(3rd edition) #22.2-8

vishalsingh: 2016-08-20 17:02:42

how one knows which test case my solution fails

Himanshu Sharma: 2016-08-14 03:12:59

single dfs, my 50th ;-[]

Surbhi: 2016-08-07 17:31:32

Why is adjacency matrix not working?

saurabh789: 2016-07-11 13:10:07

use dfs two times first time to find a node "s" which is at max distance from any child node, next time use "s" as starting node and find length of longest path

sumit suthar: 2016-07-07 14:51:28

double dfs easy one..

Suryansh Agnihotri: 2016-07-01 12:28:32

It is having weak test cases , one of my wrong solution got accepted.

ajay_raj: 2016-06-29 19:44:23

Last edit: 2016-07-01 03:48:57

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