Initial compresison.

src/compression/HuffmanEncoder.cpp

@@ -0,0 +1,77 @@
+#include "HuffmanEncoder.h"
+
+#include "Tree.h"
+
+#include <unordered_map>
+#include <queue>
+#include <tuple>
+#include <iostream>
+
+void HuffmanEncoder::encode(const HuffmanEncoder::DataStream& stream)
+{
+	std::unordered_map<unsigned char, unsigned> counts;
+	for (auto c : stream)
+	{
+		counts[c]++;
+	}
+
+	using CountPair = std::pair<unsigned char, unsigned>;
+	auto cmp = [](CountPair left, CountPair right)
+		{
+			return left.second > right.second;
+		};
+	std::priority_queue<CountPair, std::vector<CountPair>, decltype(cmp)> q(cmp);
+	for (const auto& entry : counts)
+	{
+		q.push({entry.first, entry.second});
+	}
+
+	NodePtr<CountPair> lastNode;
+	while(!q.empty())
+	{
+		const auto charData = q.top();
+		auto characterNode = std::make_unique<Node<CountPair> >(charData);
+		q.pop();
+
+		if (!lastNode)
+		{
+			const auto rightCharData = q.top();
+			auto rightCharacterNode = std::make_unique<Node<CountPair> >(rightCharData);
+			q.pop();
+
+			const auto sum = charData.second + rightCharData.second;
+			CountPair data{0, sum};
+			auto midNode = std::make_unique<Node<CountPair> >(data);
+
+			midNode->addChild(std::move(characterNode));
+			midNode->addChild(std::move(rightCharacterNode));
+			lastNode = std::move(midNode);
+		}
+		else
+		{
+			const auto sum = lastNode->getData().second;
+			CountPair data{0, sum};
+			auto midNode = std::make_unique<Node<CountPair> >(data);
+
+			if (charData.second < lastNode->getData().second)
+			{
+				midNode->addChild(std::move(lastNode));
+				midNode->addChild(std::move(characterNode));
+			}
+			else
+			{
+				midNode->addChild(std::move(characterNode));
+				midNode->addChild(std::move(lastNode));
+			}
+			lastNode = std::move(midNode);
+		}
+	}
+
+	Tree<CountPair> tree;
+	tree.addRootNode(std::move(lastNode));
+
+	//using TableEntry = std::tuple<>
+
+
+	std::cout << "********" << std::endl;
+}