Method dfs

java/1743-restore-the-array-from-adjacent-pairs.java:21–29

(Map<Integer, List<Integer>> g, int node, int[] res, Set<Integer> visited, int i)

        return res;
    }
    private static void dfs(Map<Integer, List<Integer>> g, int node, int[] res, Set<Integer> visited, int i){
        res[i++] = node;
        visited.add(node);
        
        for(int ne: g.get(node)){
            if(!visited.contains(ne))
                dfs(g, ne, res, visited, i);
        }
    }
}