广义表

广义表的实现：

#include<iostream>
#include<assert.h>
using namespace std;
enum Type
{
    HEAD,
    VALUE,
    SUB,
};
struct GeneralListNode
{
    Type _type;
    GeneralListNode* next;
    union
    {
        char _value;
        GeneralListNode* _sublink;
    };
    GeneralListNode(Type type=VALUE, char value = 0) :_type(type), next(NULL)
    {
        if (_type == VALUE)
        {
            _value = value;
        }
        else if (_type == SUB)
        {
            _sublink = NULL;
        }
    }
};
class Generalist
{

public:Generalist() :_head(NULL) {}
       ~Generalist()  
       {
           _Destory(_head); 
       }
       Generalist(char* s) :_head(NULL)
       {
           _head = _CreateGeneraList(s);
       }
       size_t size()
       {
           return _size(_head);
       }
       size_t Depth()
       {
           return _Depth(_head);
       }
       void Print()
       {
           _Print(_head);
           cout << endl;
       }
protected:
    GeneralListNode* _CreateGeneraList(char*& s)
    {
        assert(*s =='(');
        GeneralListNode* head = new GeneralListNode(HEAD);    
        ++s;
        GeneralListNode* cur = head;


        while (*s)
        {
            if (*s == '(')
            {
                GeneralListNode* subNode = new GeneralListNode(SUB);
                cur->next = subNode;
                cur = cur->next;
                subNode->_sublink = _CreateGeneraList(s);
            }
            else if (*s == ')')
            {
                ++s;
                break;
            }
            else if (ISvalue(*s))
            {
                GeneralListNode* valueNode = new GeneralListNode(VALUE, *s);
                cur->next = valueNode;
                cur = cur->next;
                ++s;
            }
            else
            {
                ++s;
            }
        }
        return head;
    }
protected:
    void _Destory(GeneralListNode* head)
    {
        GeneralListNode* cur = head;
        while (cur)
        {
            GeneralListNode* del = cur;
            cur = cur->next;
            if (del->_type == SUB)
            {
                _Destory(del->_sublink);
            }
            delete del;
        }
    }
    size_t _size(GeneralListNode* head)
    {
        GeneralListNode*cur = head;
        size_t size = 0;

        while (cur)
        {
            if (cur->_type = VALUE)
            {
                ++size;
            }
            else if (cur->_type = SUB)
            {
                size += _size(cur->_sublink);
            }
            cur = cur->next;
        }
        return size;
    }
    void _Print(GeneralListNode* head)
    {
        GeneralListNode*cur = head;
        while (cur)
        {
            if (cur->_type = HEAD)
            {
                cout << "(";
            }
            else if (cur->_type = VALUE)
            {
                cout << cur->_value;
                if (cur->next)
                {
                    cout << ",";
                }
            }
            else
            {
                _Print(cur->_sublink);
                if (cur->next)
                {
                    cout << ",";
                }
            }
            cur = cur->next;
        }
        cout << ")";
    }
    size_t _Depth(GeneralListNode* head)
    {
        size_t depth = 1;
        GeneralListNode* cur = head;

        while (cur)
        {
            if (cur->_type == SUB)
            {
                size_t subDepth = _Depth(cur->_sublink);
                if (subDepth + 1 > depth)
                {
                    depth = subDepth + 1;
                }
            }
            cur = cur->next;
        }
        return depth;
    }
public:
    bool ISvalue(char ch)
    {
        if ((ch >= '0'&&ch <= '9') || (ch >= 'a'&&ch <= 'z') || (ch >= 'A'&&ch <= 'Z'))
        {
            return true;
        }
        else
        {
            return false;
        }
    }
protected:
    GeneralListNode* _head;
};
int main()
{
    Generalist g1("()");
    Generalist g2("(a,b)");
    Generalist g3("(a,b，(c,d))");
    Generalist g4("(a,b,(c,d),(e,(f),h))");
    g4.Print();
    cout << g4.size() << endl;
    cout << g3.size() << endl;

    system("pause");
    return 0;
}