广义表的建立
/*
function:
1.Create a GeneralizedList
2.Copy a GeneralizedList
3.Get the depth of a GeneralizedList
*/
#include<iostream>
#include<string.h>
using namespace std;
typedef struct GeneralizedList
{
int tag;//case 0,single list;case 1,multi list
union{
char atom;
struct{
GeneralizedList *hp;
GeneralizedList *tp;
}Mlist;
};
}Glist;
void SubString(char *sub,char *str,int start,int number);
void CreateGlist(Glist *&T,char *str);
void server(char *substr,char *str);//find the very first commas of this string
int main()
{
char str[]="((),(e),(a,(b,c,d)))";
Glist *T;
CreateGlist(T,str);
return 0;
}
void CreateGlist(Glist *&T,char *str)
{
Glist *p,*q;
char *sub=new char[strlen(str)];
char *subtwo=new char[strlen(str)];
if(strcmp(str,"()")==0)
{
T=NULL;
}
else
{
//CreateNode
T=new Glist;T->Mlist.hp=NULL;T->Mlist.tp=NULL;
if(strlen(str)==1)
{
T->tag=0;
T->atom=str[0];
}
else
{
T->tag=1;
p=T;
//eliminate bracket
SubString(sub,str,1,strlen(str)-2);
do
{
server(subtwo,sub);//分离头尾,将头放入subtwo中，将尾放入sub中
CreateGlist(p->Mlist.hp,subtwo); q=p;//创新串
if(strlen(sub)!=0)
{
p=new Glist;p->Mlist.hp=NULL;p->Mlist.tp=NULL;
p->tag=1;
q->Mlist.tp=p;
}
}while(strlen(sub)!=0);
q->Mlist.tp=NULL;
}
}
}
void server(char *substr,char *str)
{
int k=0;//save the bracket match
int i=0,comma;
int flag=0;
int length=strlen(str);
while(str[i]!='\0'&&(k!=0||flag==0))
{
flag=0;
if(str[i]=='(') k++;
if(str[i]==')') k--;
if(str[i]==',')
{
comma=i;
flag=1;
}
i++;
}
if(i!=length)
{
SubString(substr,str,0,comma);
substr[comma]='\0';
SubString(str,str,comma+1,length);
str[length-comma-1]='\0';
}
else
{
strcpy(substr,str);
str[0]='\0';
}
}
void SubString(char *sub,char *str,int start,int number)//将从start开始的number个数字复制到sub中去
{
int i;
for(i=0;i<number;i++) sub[i]=str[start+i];
sub[i]='\0';
}