s1.c

数据结构--c语言

#include <stdio.h>
typedef enum[atom,list]elemtag;
typedef struct glnode{
	elemtag tag;
	union {
		char data;
		struct{struct glnode *hp,*tp;}ptr;
	}
}*glist;
char gl_elem(glist ls);
void createlist(glist *ls)
{
	getachar(ch);
	if(ch!='c')return 0;
	else return crtltbu(*ls);
}
void getachar(char *ch)
void crtltbu(glist *ls)
{
	getachar(ch);
	if(ch=='')
	{ls=NULL;
	getachar(ch);
	if(ch!='(') return 0;
	}
	else{
		ls=(glist)malloc(sizeof(glnode));
		ls->tag=list;
		if(isalpha(ch))
		{
			ls->hp=(glist)malloc(sizeof(glnode));
			p=s->hp;p->tag=atom;
			p->data=ch;
		}
		else if(ch=='c')crtltbu(ls->hp);
		else return 0;
		getachar(ch);
		if(ch==')')ls->tp=NULL;
		else if(ch==',')crtltbu(ls->tp);
		else return 0;
	}
}
void traverse_gl(glist ls)
{
	if(!ls)printf("()");
	else
		if(ls->tag==atom)
			printf(gl_elem(ls));
		else{
			printf('(')
				while(ls!=NULL)
				{
					traverse_gl(gethead(ls));
					ls=gettail(ls);
					if(ls)printf(',')
				}
				printf(',');
		}
}
void main()
{
	initialization();
	do{
		readcommand(cmd);
		interpret(cmd);
	}while(cm!='q'&&cmd!='Q');
}
void initialization()
{
	clrscr();
	initglist(hlink);
}
void readcommand(char cmd)
{
	do{
		cmd=getchar();
	}
	while(cmd!='c'&&cmd!='C'&&cmd!='d'&&cm!='D'&&cm!='q'&&cm!='Q');
}
void interpret(char cmd)
{
	switch(cmd)
	{
	case 'c','C':
		if(!(glistempty(hlink)))
					 destroyglist(hlink);
		createglist(hlink);
		break;
	case 'd','D':
		if(glistempty(hlink))
			else decompose(hlink,str);
		break;
	case'q','Q':
	}
}
void decompose(glist hlink,string str)
{
	n=strlen(str);p=hlink;
	for(i=0;i<n;i++)
	{
		if(!p) 
			printf("The list is a emptylist!");
		else {
			if(str[i]=='h')
			{
				p=gethead(p);
				printf("Thelisthead is:");
			}
			else
				if(str[i]=='t')
				{
					p=gettail(p);
					printf("The listtail is:");
				}
				traverse_gl(lp);
		}
	}
}