[SWEA] 2814. 최장 경로 - JAVA

문제

https://swexpertacademy.com/main/code/problem/problemDetail.do?contestProbId=AV7GOPPaAeMDFAXB 

SW Expert Academy

코드

import java.io.*;
import java.util.*;

public class Solution {
	static int n;
	static ArrayList<Integer> graph [];
	static boolean visited[];
	static int result = 1;
	
	public static void main(String[] args) throws IOException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		StringTokenizer st;
		
		int T = Integer.parseInt(br.readLine());
	
		for(int test_case = 1; test_case <= T; test_case++)
		{
			st = new StringTokenizer(br.readLine());
			n = Integer.parseInt(st.nextToken());
			int m = Integer.parseInt(st.nextToken());
			
			result = 1;
			graph = new ArrayList[n+1];
			visited = new boolean [n+1];
			
			for(int i=0;i<=n;i++) {
				graph[i] = new ArrayList<Integer>();
			}
			
			for(int i=0;i<m;i++) {
				st = new StringTokenizer(br.readLine());
				int a = Integer.parseInt(st.nextToken());
				int b = Integer.parseInt(st.nextToken());
				
				graph[a].add(b);
				graph[b].add(a);
			}
		
			for(int i=1;i<=n;i++) {
				dfs(i, 1);

			}
			System.out.println("#"+test_case+" "+result);
		}
		
	}
	
	static void dfs(int node, int count) {
		result = Math.max(result, count);

		visited[node] = true;
		for(int i=0;i<graph[node].size();i++) {
			int next = graph[node].get(i);
			if(!visited[next]) {
				dfs(next, count+1);
			}
		}
		visited[node] = false;
		
		
	}
	

}