字典树的C++实现

此次代码使用了诸多新鲜玩意，比如自动类型推断，模板类等等，感觉真的超级好玩啊。

自己做了一个简易的测试，程序的健壮性什么的还是比较差的，此程序留待以后进行功能补全。

#pragma once
#include<cstddef>
#include<string>
using std::strlen;
using std::pair;
using std::make_pair;

//字典树节点
template<int size>
class TrieNode
{
public:
    TrieNode() :NodeSize(0), TerminableSize(0)
    {
        for (size_t i = 0; i < size; i++)
        {
            ChildNode[i] = NULL;
        }
    }
    ~TrieNode()
    {
        for (size_t i = 0; i < size; i++)
        {
            delete ChildNode[i];
            ChildNode[i] = NULL;
        }
    }

public: //为了方便,此处将变量暴露,后续可以改进为通过接口操作
    int NodeSize;              //记录此节点子节点的个数
    int TerminableSize;        //存储以此节点结尾的字符串个数
    TrieNode* ChildNode[size]; //记录指向子节点的指针 
};

//字典树
template < int Size, typename Type> class Trie
{
public:
    typedef TrieNode<Size> Node;
    typedef TrieNode<Size>* pNode;

public:
    Trie() :root(new Node) {}
    ~Trie() { delete root; }

public:
    template<typename itr>
    void insert(itr beg, itr end);
    void insert(const char* str);

    template<typename itr>
    pair<bool,int> find(itr beg, itr end);
    pair<bool,int> find(const char* str);

    template<typename itr>
    bool DownNodeAlone(itr beg);

    template<typename itr>
    bool erase(itr beg, itr end);
    bool erase(const char* str);

    int sizeAll(pNode);
    int sizeNodeRedundant(pNode);

public:
    pNode root;
private:
    Type index;
};

template < int Size, typename Type>
template<typename itr>
void Trie<Size, Type>::insert(itr beg, itr end)
{
    pNode cur = root, pre = NULL;

    for (; beg != end; ++beg)
    {
        if (!cur->ChildNode[index[*beg]])
        {
            cur->ChildNode[index[*beg]] = new(Node);
            ++cur->NodeSize;
        }
        pre = cur;
        cur = cur->ChildNode[index[*beg]];
    }
    if (pre)
        ++pre->TerminableSize;
}

template < int Size, typename Type>
void Trie<Size, Type>::insert(const char* str)
{
    return insert(str, str + strlen(str));
}

template <int Size, typename Type>
pair<bool, int> Trie<Size, Type>::find(const char* str)
{
    return find(str, str + strlen(str));
}

template <int Size, typename Type>
template<typename itr>
pair<bool,int> Trie<Size, Type>::find(itr beg, itr end)
{
    pNode cur = root, pre = NULL;
    pair<bool, int> res(false, 0);
    for (;beg != end;++beg)
    {
        if (!cur->ChildNode[index[*beg]])
        {
            return res;
        }
        pre = cur;
        cur = cur->ChildNode[index[*beg]];
    }
    if (pre != NULL&&pre->TerminableSize > 0)
    {
        res.first = true;
        res.second = pre->TerminableSize;
    }
    return res;
}

template <int Size, typename Type>
template<typename itr>
bool Trie<Size, Type>::DownNodeAlone(itr beg)
{
    pNode cur = root;
    int terminableSum = 0;

    while (cur->NodeSize != 0)
    {
        terminableSum += cur->TerminableSize;
        if (cur->NodeSize > 1)
            return false;
        else
        {
            for (size_t i = 0; i < Size; i++)
            {
                if (cur->ChildNode[i])
                {
                    cur = cur->ChildNode[i];
                }
            }
        }
    }
    if (terminableSum == 1)
        return true;
    else return false;
}

template <int Size, typename Type>
template<typename itr>
bool Trie<Size, Type>::erase(itr beg, itr end)
{
    auto var = find(beg, end);
    if (var.first)
    {
        pNode cur = root, pre = NULL;
        for (; beg != end; ++beg)
        {
            if (DownNodeAlone(cur))
            {
                delete cur;
                cur = NULL;
                return true;
            }
            pre = cur;
            cur = cur->ChildNode[index[*beg]];
        }
        if (pre->TerminableSize > 0)
            --pre->TerminableSize;
        return true;
    }
    return false;
}

template <int Size, typename Type>
bool Trie<Size, Type>::erase(const char* str)
{
    auto var = find(str);
    if (var.first)
    {
        erase(str, str + strlen(str));
        return true;
    }
    return false;
}

template <int Size, typename Type>
int Trie<Size, Type>::sizeAll(pNode ptr)
{
    if (ptr == NULL)
        return 0;
    int rev = ptr->TerminableSize;
    for (size_t i = 0; i < Size; i++)
    {
        rev += sizeAll(ptr->ChildNode[i]);
    }
    return rev;
}

template <int Size, typename Type>
int Trie<Size, Type>::sizeNodeRedundant(pNode ptr)
{
    if (NULL == ptr)
        return 0;
    int i, rev = 0;
    if (ptr->TerminableSize > 0)
        rev = 1;
    if (ptr->NodeSize != 0)
    {
        for (i = 0; i < Size; ++i)
        {
            rev += sizeNodeRedundant(ptr->ChildNode[i]);
        }
    }
    return rev;
}

template<int Size>
class Index
{
public:
    Index() {}
    ~Index() {}

public:
    int operator[](char vchar)
    {
        return (vchar - 'a') % Size;
    }
};

测试：

int main(void)
{
    {
        Trie<26, Index<26>> temp;
        temp.insert("hello");
        temp.insert("he");
        temp.insert("he");
        temp.insert("her");
        temp.insert("him");
        temp.insert("fuck");
        temp.insert("fuckyou");
        temp.insert("hupu");
        temp.insert("lady");
        temp.insert("hahah");
        temp.insert("lady");
        temp.insert("lady");
        temp.insert("lady");

        auto var = temp.find("lady");
        cout << "lady:" << boolalpha <<var.first <<" "<<var.second<< endl;
        var = temp.find("heihei");
        cout << "heihei:" << boolalpha << var.first << " " << var.second << endl;

        cout << "size:" << temp.sizeAll(temp.root) << endl;
        cout << "size of NoneRedundant:" << temp.sizeNodeRedundant(temp.root) << endl;

        var = temp.find("hupu");
        cout << "hupu:" << boolalpha << var.first <<" "<<var.second<< endl;
        temp.erase("hupu");
        var = temp.find("hupu");
        cout << "hupu:" << boolalpha << var.first << " " << var.second << endl;

        cout << "size:" << temp.sizeAll(temp.root) << endl;
        cout << "size of NoneRedundant:" << temp.sizeNodeRedundant(temp.root) << endl;
    }

    cin.get();
    _CrtDumpMemoryLeaks();
    return 0;
}