从零开始写STL—set/map

这一部分只要把搜索树中暴露的接口封装一下，做一些改动。

set源码剖析

	template<typename T>
	class set
	{
	public:
		typedef T key_type;
		typedef BStree_iterator<T> iterator;
	private:
		BStree<T> sequence;
	public:
		set() :sequence() {}
		iterator begin()
		{
			return sequence.begin();
		}
		iterator end()
		{
			return sequence.end();
		}
		void erase(iterator pos)
		{
			if (pos.p.node == NULL)
				return;
			sequence.erase(pos);
		}
		iterator find(const key_type& key)
		{
			return sequence.find(key);
		}
		size_t count(const key_type& x)
		{
			iterator pos = sequence.find(x);
			if (pos.p.node == NULL)
				return 0;
			else
				return 1;
		}
		size_t erase(const key_type& x)
		{
			iterator pos = sequence.find(x);
			if (pos.p.node == NULL)
				return 0;
			else
			{
				erase(pos);
				return 1;
			}
		}

		bool empty()
		{
			return sequence.empty();
		}
		size_t size()
		{
			return sequence.size();
		}
		iterator insert(const T& val)
		{
			iterator f = sequence.find(val);
			if (f == NULL)
				return sequence.insert(val);
			else
				return f;
		}
		iterator lower_bound(const key_type& x)
		{
			return sequence.lower_bound(x);
		}
		iterator upper_bound(const key_type& x)
		{
			return sequence.upper_bound(x);
		}
	};

map

二叉搜索树中存储的元素—map_pair

template<typename K, typename T>
	struct map_pair
	{
		typedef map_pair<K, T> self;
		K first;
		T second;
		operator pair<K, T>()
		{
			return ministl::make_pair<K, T>(first, second);
		}
		map_pair(const pair<K, T>& rhs)
		{
			first = rhs.first;
			second = rhs.second;
		}
		map_pair(const K& key, const T& val)
		{
			first = key, second = val;
		}
		bool operator==(const self& rhs) const
		{
			return first == rhs.first;
		}
		bool operator!=(const self& rhs) const
		{
			return !(*this == rhs);
		}
		bool operator<(const self& rhs) const
		{
			return first < rhs.first;
		}
		bool operator>(const self& rhs) const
		{
			return first > rhs.first;
		}
		bool operator>=(const self& rhs) const
		{
			return !(first < rhs.first);
		}
		bool operator<=(const self& rhs) const
		{
			return !(first > rhs.first);
		}
	};

map源码

	template<typename K, typename T>
	class map
	{
	private:
		typedef map_pair<K, T> key_value;
		typedef size_t size_type;
		BStree<key_value> sequence;
	public:
		typedef BStree_iterator<key_value> iterator;
		map() :sequence() {}
		iterator begin()
		{
			return sequence.begin();
		}
		iterator end()
		{
			return sequence.end();
		}
		bool empty()
		{
			return sequence.empty();
		}
		size_type size()
		{
			return sequence.size();
		}
		iterator find(const K& x)
		{
			return sequence.find(map_pair<K, T>(x, T()));
		}
		size_type count(const K& x)
		{
			if (sequence.find(map_pair<K, T>(x, T())).p.node == NULL)
				return 0;
			else
				return 1;
		}
		auto insert(const key_value& key)
		{
			return sequence.insert(map_pair<K,T>(key,T()));
		}
		template <class InputIterator>
		void insert(InputIterator first, InputIterator last)
		{
			for (auto it = first; it != last; it++)
				insert(*first);
		}
		void erase(const K& key)
		{
			return sequence.erase(map_pair<K, T>(key, T()));
		}
		iterator upper_bound(const K& key)
		{
			return sequence.upper_bound(map_pair<K, T>(key, T()));
		}
		iterator lower_bound(const K& key)
		{
			return sequence.lower_bound(map_pair<K, T>(key, T()));
		}


		T& operator [](const K& x)
		{
			pair<iterator,bool> res = sequence.insert(map_pair<K,T>(x,T()));
			return (*res.first).second;
		}

	};