Function backTrack

javascript/0269-alien-dictionary.js:169–177

(char, graph, seen, buffer)

};

const backTrack = (char, graph, seen, buffer) => {
    seen.set(char, false);
    for (const neighbor of graph.get(char)) {
        if (!dfs(neighbor, graph, seen, buffer)) return false;
    }
    seen.set(char, true);

    return true;
};