广义表

#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<assert.h>
using namespace std;

enum NODETYPE
{
HEAD,
VALUE,
SUB
};

struct GeneralizedNode
{

NODETYPE _type;
GeneralizedNode* _next;
union
{
char _value;
GeneralizedNode* _sublist;
};

GeneralizedNode(NODETYPE type = HEAD, char value = 0)
:_type(type)
, _next(NULL)
{

if (_type == VALUE)
{
_value = value;
}
else if (_type == SUB)
{
_sublist = NULL;
}

}
};

class GeneralizedList
{

public:
GeneralizedList(const char* str)
{
_head = _CreateList(str);
}

~GeneralizedList()
{
_Clean(_head);
}

void Print()
{
_Print(_head);
cout << endl;
}

void Size()
{
cout<<_Size(_head)<<endl;
}

protected:
GeneralizedNode* _CreateList(const char*& str) //这里的str为二级指针 所以要用引用
{
assert(*str == '(');

GeneralizedNode* head = new GeneralizedNode(HEAD);
GeneralizedNode* cur = head;
str++; //方便处理 开始 和 字链表 这两种情况

// 一搬情况：
// (a,b,c)
// (a,(b,c),d)
// (a, b,c)
// ()
// (())
// 1:值 2：‘（’ 3：‘）’ 4：逗号 空格等等无关符号
while (*str != NULL)
{
if (_IsValue(*str)) // 是值的情况
{
GeneralizedNode* tem = new GeneralizedNode(VALUE, *str);
cur->_next = tem;
cur = tem;
str++;
}
else if (*str == '(') // 是子链表的情况
{
GeneralizedNode* sub = new GeneralizedNode(SUB);
cur->_next = sub;
cur = sub;

sub->_sublist = _CreateList(str);//循环构造子链
}
else if (*str == ')') //子表结束的情况
{
str++;
return head;
}
else //逗号 空格等等无关符号的情况
{
str++;
}
}
return head;
}

bool _IsValue(char ch)
{
if ((ch >= '0' && ch <= '9') || \
(ch >= 'a' && ch <= 'z') || \
(ch >= 'A' && ch <= 'Z'))
{
return true;
}
else
{
return false;
}
}

void _Print(GeneralizedNode* head)
{
GeneralizedNode* cur = head;

while (cur != NULL)
{
if (cur->_type == HEAD)
{
cout << "(";
}
else if (cur->_type == VALUE)
{
cout << cur->_value;
if (cur->_next != NULL)
{
cout << ",";
}
}
else
{
_Print(cur->_sublist);
cout << ","; //注意子链打印完了也要打印一个 ，
}
cur = cur->_next;
}

cout << ")";
}

int _Size(GeneralizedNode* head)
{
//assert(head);
int count = 0;

GeneralizedNode* cur = head;
while (cur != NULL)
{
//if (cur->_type == HEAD)
//{
// cur = cur->_next; //下面有这个操作 可以合并
//}
if (cur->_type == VALUE)
{
count++;
}
else if (cur->_type == SUB)
{
count += _Size(cur->_sublist);
}
cur = cur->_next;
}

return count;
}

void _Clean(GeneralizedNode* head)
{
GeneralizedNode* cur = head;

while (cur != NULL)
{
GeneralizedNode* del = cur;

if (cur->_type == HEAD || cur->_type == VALUE)
{
cur = cur->_next;
delete(del);
}
else
{
_Clean(cur->_sublist);
cur = cur->_next;
}
}
}
protected:
GeneralizedNode* _head;

};

void Test1()
{
char* s1 = "(a,b,c,d)";
char* s2 = "(a,(b,c),d)";
char* s3 = "(())";

GeneralizedList L1(s1);
GeneralizedList L2(s2);
GeneralizedList L3(s3);

L1.Print();
L2.Print();
L3.Print();

L1.Size();
L2.Size();
L3.Size();
}

int main()
{
Test1();
return 0;
}