2368. Reachable Nodes With Restrictions 

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class Solution {
    public int reachableNodes(int n, int[][] edges, int[] restricted) {
        Map<Integer, List<Integer>> nodeToNodeListMap = new HashMap<>();
        for (int i = 0; i < n; i++) {
            nodeToNodeListMap.put(i, new ArrayList<>());
        }
        for (int[] edge : edges) {
            int nodeA = edge[0], nodeB = edge[1];
            nodeToNodeListMap.get(nodeA).add(nodeB);
            nodeToNodeListMap.get(nodeB).add(nodeA);
        }

        int reachableNodes = 0;

        Set<Integer> visitedSet = new HashSet<>();
        for (int r : restricted) {
            visitedSet.add(r);
        }
        Queue<Integer> queue = new LinkedList<>();
        queue.add(0);

        while (!queue.isEmpty()) {
            int node = queue.poll();
            visitedSet.add(node);
            reachableNodes++;

            for (int neighbor : nodeToNodeListMap.get(node)) {
                if (visitedSet.contains(neighbor)) {
                    continue;
                }

                queue.offer(neighbor);
            }
        }

        return reachableNodes;
    }
}

References

2368. Reachable Nodes With Restrictions