{

std::priority_queue<HuffmanNode*, std::vector<HuffmanNode*>, MinComparator> min_queue;

for (auto [freq, ch] : freq_map)

{

min_queue.push(new HuffmanNode{freq, ch, freq});

}

while (static_cast<int>(min_queue.size()) != 1)

{

const auto left = min_queue.top();

min_queue.pop();

const auto right = min_queue.top();

min_queue.pop();

const int key = left->key + right->key;

auto node = new HuffmanNode{key, '-', left->freq + right->freq};

node->left = left;

node->right = right;

min_queue.push(node);

}

return min_queue.top();

{

if (root == nullptr)

{

return;

}

if (root->ch != '-')

{

result.insert(std::pair(root->ch, code));

}

TraversalHuffmanCode(root->left, code + "0", result);

TraversalHuffmanCode(root->right, code + "1", result);