Function dfs

javascript/0269-alien-dictionary.js:159–167

(char, graph, seen, buffer)

};

const dfs = (char, graph, seen, buffer) => {
    if (seen.has(char)) return seen.get(char);

    if (!backTrack(char, graph, seen, buffer)) return false;

    buffer.push(char);

    return true;
};

const backTrack = (char, graph, seen, buffer) => {
    seen.set(char, false);