广义表

#include<stdio.h>

#include<malloc.h>

#include<windows.h>

typedef char elemtype;

typedef struct lnode //广义表的定义

{

int tag;

union

{

elemtype data;

struct lnode *sublist;

}val;

struct lnode *link;

}glnode;

glnode *creategl(char *&s) //建立广义表的链式存储结构

{

glnode *g;

char ch=*s++;

if(ch!='\0')

{

g=(glnode *)malloc(sizeof(glnode));

if(ch=='(')

{

g->tag=1;

g->val.sublist=creategl(s);

}

else if(ch==')')

g=NULL;

else if(ch=='#')

g=NULL;

else

{

g->tag=0;

g->val.data=ch;

}

}

else

g=NULL;

ch=*s++;

if(g!=NULL)

if(ch==',')

g->link=creategl(s);

else

g->link=NULL;

return g;

}

int gllength(glnode *g) //求广义表的长度

{

int n=0;

glnode *g1;

g1=g->val.sublist;

while(g1!=NULL)

{

n++;

g1=g1->link;

}

return n;

}

int gldepth(glnode *g) //求广义表的深度

{

glnode *g1;

int max=0,dep;

if(g->tag==0)

return 0;

g1=g->val.sublist;

if(g1==NULL)

return 1;

while(g1-NULL)

{

if(g1->tag==1)

{

dep=gldepth(g1);

if(dep>max)

max=dep;

}

g1=g1->link;

}

return(max+1);

}

elemtype maxatom(glnode *g) //求广义表中的最大原子

{

elemtype 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);

}

}

else

return 0;

}

void dispgl(glnode *g) //输出广义表

{

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);

}

}

}

void main()

{

glnode *g;

char a[100],*p=a;

int m;

printf(" *************欢迎使用广义表的运算系统****************\n");

printf("请输入一个广义表:(例如(b,(b,a,(#),d),((a,b),c,((#)))))\n");

gets(a);

g=creategl(p);

printf("广义表已建好\n");

while(1)

{

printf("请选择:");

printf(" 1求广义表的长度\n");

printf(" 2求广义表的深度\n");

printf(" 3输出广义表\n");

printf(" 4求广义表中的最大原子\n");

printf(" 5退出\n");

scanf("%d",&m);

switch(m)

{

case 1:printf("广义表的长度为:%d\n",gllength(g));break;

case 2:printf("广义表的深度为:%d\n",gldepth(g));break;

case 3:printf("广义表为:");dispgl(g);printf("\n");break;

case 4:printf("广义表中的最大原子为:%c\n",maxatom(g));break;

case 5:exit(0);

default:printf("输入错误\n");

}

}

}