检索树

标签：检索树

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

#define MAX_LETTERS 27
#define MAX_CHAR 30//字符串的长度


typedef enum  {data,pointer}node_type;
typedef struct trie_node *trie_pointer;
struct trie_node
{
	int child;
	node_type tag;
	union{
		char*key;
		trie_pointer letters[MAX_LETTERS];
	}u;
};

int get_index(char*key,int i);
void insert(trie_pointer t,char*key,int i);
void insert_two(trie_pointer t,char*key,trie_pointer oldkey,int i);
trie_pointer newnode();
trie_pointer newnodekey(char*);/*指针结构体*/
trie_pointer search(trie_pointer t,char* key,int i);
trie_pointer del(trie_pointer r,char* key,int i);
void look(trie_pointer r,char*key);

void main()
{
	trie_node root;
	root.child=1;
	root.tag=pointer;
	for (int i = 0; i < MAX_LETTERS; ++i)
		root.u.letters[i]=NULL;
	
	insert(&root,"bluebird",0);
	insert(&root,"bunting",0);
	insert(&root,"bluejay",0);
	insert(&root,"bobwhite",0);

	insert(&root,"luebird",0);
	insert(&root,"ting",0);
	insert(&root,"lujay",0);
	insert(&root,"bobwte",0);	
	insert(&root,"aluebird",0);
	insert(&root,"ung",0);
	insert(&root,"ejay",0);
	insert(&root,"white",0);	
	insert(&root,"ebird",0);
	insert(&root,"tig",0);
	insert(&root,"bluejay",0);
	insert(&root,"bobwh",0);


    look(&root,"aaa");
    look(&root,"bluebird");

    look(&root,"bobwhite");
	del(&root,"bobwhite",0);
	look(&root,"bobwhite");

	look(&root,"bunting");
	del(&root,"bunting",0);
	look(&root,"bunting");

	del(&root,"aaaa",0);

}

void insert(trie_pointer t,char*key,int i){
	int ki=get_index(key,i);
	trie_pointer n=t->u.letters[ki];

	if (n == NULL)
	{
		trie_pointer n=newnodekey(key);
		t->u.letters[ki]=n;/*结构体加进去*/
		++t->child;
	}
	else{/*这个区有东西*/

		if (n->tag == pointer)/*u中是指针*/
		{
			insert(n,key,i+1);
		}
		else{/*u中是key*/

			if(! strcmp(key,n->u.key)){
				printf("已经存在%s\n",key );
				return;
			}
			insert_two(t,key,t->u.letters[ki],i);

		}
	}
}
int get_index(char*key,int i){
	if (key[i]==NULL)
	  return 0;
	return tolower(key[i]) - 'a'+1;
}
void insert_two(trie_pointer t,char*key,trie_pointer oldkey,int i){
	trie_pointer n;
	do{
		
		n= newnode();/*未处理新申请的*/		
		t->u.letters[get_index(key,i)]=n;/* 放入原始区，所以不用i+1 */
		t=n;
		++i;
		
	}while(key[i] == oldkey->u.key[i]);

	t->u.letters[get_index(oldkey->u.key,i)]=oldkey;/*原来的值*/

    n=newnodekey(key);
	t->u.letters[get_index(key,i)]=n;/*新的值*/
	++t->child;

}
trie_pointer newnode(){/*指针结构体*/
	trie_pointer n;
	n= (trie_pointer)malloc(sizeof(struct trie_node));/*处理新申请的*/
	for (int i = 0; i < MAX_LETTERS; ++i)
	n->u.letters[i]=NULL;
	n->tag=pointer;
  return n;
}
trie_pointer newnodekey(char* charkey){/*值结构体*/
	char *c=(char*)malloc(sizeof(char)* (strlen(charkey)+1) );/*注意释放*/
	strcpy(c,charkey);
	trie_pointer n= (trie_pointer)malloc(sizeof(struct trie_node));
	n->u.key=c;
	n->tag=data;/*新值的标配*/
	n->child=1;

	return n;
}
trie_pointer search(trie_pointer t,char* key,int i){
	if (!t)return NULL;
	if (t->tag==data)
		return (strcmp(t->u.key,key))?NULL:t;
	return search(t->u.letters[get_index(key,i)],key,i+1);
}
void look(trie_pointer r,char*key){
	trie_pointer k;
	if (k=search(r,key,0)){	
		printf("存在%s\n",k->u.key);
	}
	else{
		printf("不存在%s\n",key);
	}

}

trie_pointer del(trie_pointer r,char* key,int i){
 
    trie_pointer t=r->u.letters[get_index(key,i)];
    trie_pointer re=NULL;
	if(!t){
		 printf("不存在要删除的值");
		 return NULL;
	}

	if (t->tag==data)
	{
		if (!strcmp(t->u.key,key))/*定位ok，即可删除*/
		{
			free(t->u.key);
			free(t);
			--r->child;/*减一*/
			r->u.letters[get_index(key,i)]=NULL;/*置为NULL*/

			if (r->child==1){/*只是剩下一个值了*/
				for (int i = 0; i < MAX_LETTERS; ++i)
					if(r->u.letters[i]!=NULL)
						return r->u.letters[i];
			}
			return NULL;
		}
		else{/*是值了，但是不相同*/
		 printf("不存在要删除的值");
		 return NULL;
		}
	}
re=del(t,key,i+1);
	if( re!=NULL)/*返回非NULL。执行*/
	{
		free(r->u.letters[get_index(key,i)]);
		if (r->child == 1)
			return re;
		else{
			r->u.letters[get_index(key,i)]=re;
			return NULL;
		}
	}
return NULL;
}

检索树

标签：检索树

原文地址：http://blog.csdn.net/h1023417614/article/details/41896605