用Trie树实现词频统计和单词查询

/*
文件名: trie.c
功能描述:用trie树实现单词词频统计以及单词查询
说明:
对统计对象,要求符合正则"[a-z]*"的格式的单词
若考虑大写,标点和空白字符(空格.TAB.回车换行符),
可修改next数组大小,最多255可包含所有字符
*/

#include <stdio.h>
#include <stdlib.h>
#include <memory.h>

typedef struct Trie_node_stru
{
int  count; //记录该处终结的单词个数
struct Trie_node_stru *next[26];//指向各个子树的指针,下标0-25代表26字符

}TrieNode, *Trie;

TrieNode* trie_createTrieNode()
{
TrieNode* tmp = (TrieNode*)malloc(sizeof(TrieNode));
tmp->count = 0;
memset(tmp->next, 0, sizeof(tmp->next));
return tmp;
}

int trie_insert(Trie root, char* word)
{
TrieNode* node = root;
char *p = word;
while(*p)
{
if(NULL == node->next[*p-'a'])
{
node->next[*p-'a'] = trie_createTrieNode();
}
node = node->next[*p-'a'];
p++;
}
node->count += 1;
printf("%-20s appears for %d time(s) in the Trie!\r\n",
word, node->count);
return 0;
}

int trie_search(Trie root, char* word)
{
TrieNode* node = root;
char *p = word;
while(*p && NULL!=node)
{
node = node->next[*p-'a'];
p++;
}
return (node!=NULL && node->count>0);
}

int trie_remove(Trie root, char* word)
{
//TODO
return 0;
}

int main()
{
Trie t = trie_createTrieNode();
trie_insert(t, "a");
trie_insert(t, "abc");
char * c = "test";
trie_insert(t, c);
trie_insert(t, "testonly");
trie_insert(t, "testonly");
trie_insert(t, "a");

printf("====================\r\n");
if(trie_search(t, "a"))
printf("true\n");
else
printf("false\n");
if(trie_search(t, "testnly"))
printf("true\n");
else
printf("false\n");

return 0;
}