正在学习数据结构广义表解决办法

正在学习数据结构广义表
自己按书上摸索写了几个函数，请大家给点意见

C/C++ code

#ifndef _GLIST_H#define _GLIST_H#include <stdlib.h>#include <stdarg.h>typedef int AtomType;typedef enum  {    ATOM,    LIST  } ElemTag;typedef struct glnode{  ElemTag tag;  union  {    AtomType atom;    struct {      struct glnode *head,*tail;        } ptr;  };} GLIST,*GLP;GLP MakeGNode(ElemTag tag,...);int CreateGList(GLP gp,const char *table);int GetGListDepth(const GLP gp);int CopyGList(const GLP gsrc,GLP gdst);int GListTraverse(const GLP gp,void visit(const GLP));int ExportGList(const GLP gp,char *cp);#endif//_GLIST_H#include <stdio.h>#include <stdlib.h>#include <string.h>#include "glist.h"void visit(const GLP gp);void ExportGLP(GLP gp,char *cp,int from);int main(){  char *cp="((),((2,4),(5,3,(1,2))),(1),((2,(3,4,5))),(2,(3,4,5)))";  puts(cp);  GLIST g1,g2;  CreateGList(&g1,cp);  GListTraverse(&g1,visit);  CopyGList(&g1,&g2);  char ch[100];  memset(ch,0,100);  ExportGList(&g2,ch);  puts(ch);  return 0;}GLP MakeGNode(ElemTag tag,...){  GLP gp=(GLP)malloc(sizeof(GLIST));  if (!gp)  {    printf("not enough memory\n");    exit(2);  }  gp->tag=tag;  va_list ap;  va_start(ap,tag);  if (tag==ATOM)    gp->atom=va_arg(ap,AtomType);  va_end(ap);  return gp;}int CreateGList(GLP gp,const char *cp){  if (strchr(cp,'(')==NULL)//原子  {    gp->tag=ATOM;    gp->atom=atoi(cp);    return 0;  }  gp->tag=LIST;  char ht[100],tt[100];  GetFirstTable(cp,ht,tt);  if (strcmp(ht,"()")!=0)  {    gp->ptr.head=(GLP)malloc(sizeof(GLIST));    CreateGList(gp->ptr.head,ht);  }  else    gp->ptr.head=NULL;  if (strcmp(tt,"()")!=0)  {    gp->ptr.tail=(GLP)malloc(sizeof(GLIST));    CreateGList(gp->ptr.tail,tt);  }  else    gp->ptr.tail=NULL;}int GetFirstTable(const char *cp,char *ht,char *tt){  int pt,pos,len=strlen(cp);  if (cp[1]=='(')  {    pt=1;    pos=2;    while (pt!=0)    {      if (cp[pos]=='(')        pt++;      if (cp[pos]==')')        pt--;      pos++;    }  }  else  {    pos=1;    while (cp[pos]!=',' && pos<len-1)      pos++;  }  strncpy(ht,cp+1,pos-1);  ht[pos-1]='\0';  tt[0]='(';  strncpy(tt+1,cp+pos+1,len);  if (tt[1]=='\0')    tt[1]=')';  return 0;}int CopyGList(const GLP gsrc,GLP gp){  gp->tag=gsrc->tag;  if (gsrc->tag==ATOM)  {    gp->atom=gsrc->atom;    return 0;  }  if (gsrc->ptr.head!=NULL)  {    gp->ptr.head=(GLP)malloc(sizeof(GLIST));    CopyGList(gsrc->ptr.head,gp->ptr.head);  }  else    gp->ptr.head=NULL;  if (gsrc->ptr.tail!=NULL)  {    gp->ptr.tail=(GLP)malloc(sizeof(GLIST));    CopyGList(gsrc->ptr.tail,gp->ptr.tail);  }  else    gp->ptr.tail=NULL;}int GListTraverse(const GLP gp,void visit(const GLP gpp)){  visit(gp);  if (gp)  {    if (gp->tag==LIST)    {      printf("head:");      GListTraverse(gp->ptr.head,visit);      printf("tail:");      GListTraverse(gp->ptr.tail,visit);    }  }}void visit(const GLP gp){  if (!gp)  {    printf("NULL\n");    return;  }  if (gp->tag==LIST)  {    printf("LIST->");    return;  }  printf("ATOM(%d)\n",gp->atom);}int ExportGList(const GLP gp,char *cp){  ExportGLP(gp,cp,0);  return 0;}void ExportGLP(GLP gp,char *cp,int from){  static pos=0;  if (!gp)  {    if (from==0)    {      cp[pos++]='(';      cp[pos++]=')';    }    return;  }  if (from==0)  {    if (gp->tag==LIST)    {      cp[pos++]='(';      ExportGLP(gp->ptr.head,cp,0);      if (gp->ptr.tail==NULL)        cp[pos++]=')';      else        cp[pos++]=',';      ExportGLP(gp->ptr.tail,cp,1);    }    else    {      cp[pos++]=gp->atom+'0';      return;    }  }  else  {    ExportGLP(gp->ptr.head,cp,0);    if (gp->ptr.tail==NULL)      cp[pos++]=')';    else      cp[pos++]=',';    ExportGLP(gp->ptr.tail,cp,1);  }}