Leetcode Trie Tree实现问题.

Question

1. 这个算法是要实现一个trie tree, 但是我好像遇到了内存分配的问题，主要我是想要c语言实现. 报错信息的话，可以直接跑我那面那段代码，看看有什么问题。

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

   #define MAX_SIZE 26

   struct TrieNode {

      struct TrieNode *children[MAX_SIZE];
      bool isWord;

   };

   struct TrieNode* newTrieNode() {

      struct TrieNode *node = (struct TrieNode *)malloc(sizeof(struct TrieNode *));
      if (node == NULL)
          exit(1);
      int i;
      memset(node->children, 0x0, sizeof(struct TrieNode *)*26);
      node->isWord = false;
      return node;

   }

   void insert(struct TrieNode root, char word) {

      int i, length, index;
      length = strlen(word);
      if (length <= 0) return;
      struct TrieNode *current = root;
      for (i = 0; i < length; i++) {
          index = word[i] - 'a';
          if (current->children[index] == NULL) {
              current->children[index] = newTrieNode();
          }
          current = current->children[index];
      }
      current->isWord = true;

   }

   bool search(struct TrieNode root, char word) {

      int i, length, index;
      length = strlen(word);
      if (length <= 0) return true;
      struct TrieNode *current = root;
      for (i = 0; i < length; i++) {
          index = word[i] - 'a';
          current = current->children[index];
          if (current == NULL) return false;
      }
      return current->isWord;

   }

   int main() {

      struct TrieNode *root = newTrieNode();
      insert(root, "hello");
      printf("%d\n", search(root, "hello"));
      free(root);
      return 0;

   }

Answer 1

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

#define MAX_SIZE 26

struct TrieNode {

    struct TrieNode* children[MAX_SIZE];
    bool isWord;
};

struct TrieNode* newTrieNode()
{

    //你要分配的类型 是TrieNode, 不是指针，不要搞错了
    //struct TrieNode* node = (struct TrieNode*)malloc(sizeof(struct TrieNode*));
    struct TrieNode* node = (struct TrieNode*)malloc(sizeof(struct TrieNode));
    if (node == NULL)
        exit(1);
    int i;
    memset(node->children, 0x0, sizeof(struct TrieNode*) * 26);
    node->isWord = false;
    return node;
}

//void insert(struct TrieNode root, char word)// -- 参数都应该是指针
void insert(struct TrieNode* root, char* word)
{

    int i, length, index;
    length = strlen(word);
    if (length <= 0)
        return;
    struct TrieNode* current = root;
    for (i = 0; i < length; i++) {
        index = word[i] - 'a';
        if (current->children[index] == NULL) {
            current->children[index] = newTrieNode();
        }
        current = current->children[index];
    }
    current->isWord = true;
}

//bool search(struct TrieNode root, char word)// -- 参数是指针
bool search(struct TrieNode* root, char* word)
{

    int i, length, index;
    length = strlen(word);
    if (length <= 0)
        return true;
    struct TrieNode* current = root;
    for (i = 0; i < length; i++) {
        index = word[i] - 'a';
        current = current->children[index];
        if (current == NULL)
            return false;
    }
    return current->isWord;
}

其它没什么问题 ～

int main()
{

    struct TrieNode* root = newTrieNode();
    insert(root, "hello");
    printf("%d\n", search(root, "hello"));
    free(root);
    return 0;
}