Function queueSources

javascript/0269-alien-dictionary.js:89–96

(queue, frequencyMap)

};

const queueSources = (queue, frequencyMap) => {
    for (const [key, value] of frequencyMap) {
        const isEmpty = frequencyMap.get(key) === 0;
        if (!isEmpty) continue;

        queue.enqueue(key);
    }
};

/**
 * DFS