DFS Graph Traversal IK Solution Correction

package com.brent.ik.graphs;

import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.LinkedList;
import java.util.*;

public class DFS {

    static void dfsTraversalHelper(int startNode, List<List<Integer>> graph, List<Integer> answer, boolean[] isVisited) {
        isVisited[startNode] = true;
//        answer.add(startNode);
        Deque<Integer> stack = new ArrayDeque<>();
        stack.push(startNode);

        while (stack.size() > 0) {
            int u = stack.pop();
            answer.add(u); // the only place it should be, when it comes off the queue
            for (int v : graph.get(u)) {
                if (!isVisited[v]) {
//                    answer.add(startNode);
                    stack.push(v);
                    isVisited[v] = true;
                }
            }
        }
    }

    public static List<Integer> dfs_traversal(int n, List<List<Integer>> edges) {
        List<List<Integer>> graph = new ArrayList<>();
        List<Integer> answer = new ArrayList<>();
        boolean[] isVisited = new boolean[n];

        // Initialize graph
        for (int i = 0; i < n; i++) {
            graph.add(new ArrayList<>());
        }

        // Making a graph from the input edges
        for (List<Integer> edge : edges) {
            int u = edge.get(0);
            int v = edge.get(1);
            graph.get(u).add(v);
            graph.get(v).add(u); // For undirected graph
        }

        for (int i = 0; i < n; i++) {
            if (!isVisited[i]) {
                dfsTraversalHelper(i, graph, answer, isVisited);
            }
        }

        return answer;
    }
}