广义表的基本操作

#include 
#include
#include
typedef struct lnode
{
	int tag;
	union
	{
		char data;
		struct lnode *sublist;
	}val;
	struct lnode *link;
}GLNode;

GLNode *CreatGL(char *&s)
{
	GLNode *g;
	char ch=*s++;
	if(ch!='\0')
	{
		g=(GLNode*)malloc(sizeof(GLNode));
		if(ch=='(')
		{
			g->tag=1;
			g->val.sublist=CreatGL(s);
		}
		else if(ch==')')
		{
			g=NULL;
		}
		else if(ch=='#')
		g->val.sublist=NULL;
		else
		{
			g->tag=0;
			g->val.data=ch;
		}
		
	}
	else
		g=NULL;
		ch=*s++;
		if(g!=NULL)
		   if(ch==',')
		   g->link=CreatGL(s);
		   else
		   g->link=NULL;
		   return g;
}

int GLLength(GLNode *g)
{
	int n=0;
	g=g->val.sublist;
	while(g!=NULL)
	{
		n++;
		g=g->link;
	}
	return n;
}


int GLDepth(GLNode *g)
{
	int maxd=0,n=0;
	if(g->tag==0)
	return 0;
	g=g->val.sublist;
	if(g==NULL)
	return 1;
	while(g!=NULL)
	{
		if(g->tag==1)
		{
		    n=GLDepth(g);
	    	if(n>maxd)
	    	maxd=n;
		}
		g=g->link;
	}
	return (maxd+1);
}

void DispGL(GLNode *g)
{
	if(g!=NULL)
	{
		if(g->tag==0)
		printf("%c",g->val.data);
		else
		{
			printf("(");
			if(g->val.sublist==NULL)
			printf("#");
			else
			DispGL(g->val.sublist);
			printf(")");
		}
		if(g->link!=NULL)
		{
			printf(",");
			DispGL(g->link);
    	}		
	}
}
	
char maxatom(GLNode *g)
{
	char max1,max2;
	if(g!=NULL)
	{
		if(g->tag==0)
		{
			max1=maxatom(g->link);
			return (g->val.data>max1?g->val.data:max1);
		}
		else
		{
			max1=maxatom(g->val.sublist);
			max2=maxatom(g->link);
			return (max1>max2?max1:max2);
		}
	}
}

void DestroyGL(GLNode *&g)
{
	GLNode *g1,*g2;
	g1=g->val.sublist;
	while(g1!=NULL)
	{
		if(g1->tag==0)
		{
			g2=g1->link;
			free(g1);
			g1=g2;
		}
		else
		{
			g2=g1->link;
			DestroyGL(g1);
			g1=g2;
		}
	}
	free(g);
	
}	

int main()
{
	GLNode *g;
	char *str="(k,(b,a,(#),d),((a,b),c,((#))))";
	g=CreatGL(str);
	printf("广仪表");
	DispGL(g);
	printf("\n");
	printf("changdu %d\n",GLLength(g));
	printf("changdu %d\n",GLDepth(g));
	printf("%c",maxatom(g));
	DestroyGL(g);
	return 0;
}