我有一個文件,其中包含一個txt文件中的英文單詞,每個單詞換行。我使用load
和unload
函數將所有單詞存儲到散列表(單獨的鏈接)中,並將它們從內存中卸載,但遇到了一些問題。將單詞存儲到哈希表中
功能(main.c中的代碼是正確的):
負載:
#include <stdbool.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <stdio.h>
#include "dictionary.h"
#define SIZE 26
typedef struct node
{
char word[LENGTH+1];
struct node *next;
}node;
unsigned int hash_num = 0;
node *hashtable[SIZE]; //26 letters in alphabet
node *head = NULL;
// hashfunction
unsigned int hash(char const *key)
{
unsigned int hash= tolower(key[0]) - 'a';
return hash % SIZE;
}
/**
* Loads dictionary into memory. Returns true if successful else false.
*/
bool load(const char* dictionary)
{
unsigned int hash_index=0;
FILE *fp = fopen(dictionary, "r");
if(fp == NULL)
{
fprintf(stderr, "Couldn't open %s",dictionary);
return false;
}
//dictionary
while(!feof(fp))
{
node *temp = malloc(sizeof(node));
if (temp == NULL)
{
unload();
fclose(fp);
return false;
}
if(fscanf(fp , "%s", temp->word) == 1) //storing word of dictionary in my new_node -> word
{
hash_index = hash(temp->word);
head= hashtable[hash_index]; //head always points to first element of linked list (containting word of dictionary)
temp->next = head;
head = temp;
hash_num++;
}
else //if fscanf couldn't store the word (return 0)
{
free(temp); //free last temp
break;
}
}
fclose(fp);
return true;
}
卸載:
bool unload(void)
{
for(int i=0; i<SIZE; i++)
{
if(hashtable[i] != NULL) //if hashtable isn't NULL (has nodes)
{
node *cursor = hashtable[i]; //cursor points at head of individual linked list
while(cursor != NULL) //free them
{
node *temp = cursor;
cursor = cursor->next;
free(temp);
}
}
}
return true;
}
誰能告訴我如果邏輯 是正確的?每當我運行valgrind時,它告訴我所有的節點都已分配,但只有3個free'd。
total heap usage: 143,094 allocs, 3 frees, 8,014,288 bytes allocated
LEAK SUMMARY:
==15903== definitely lost: 8,013,040 bytes in 143,090 blocks
==15903== indirectly lost: 0 bytes in 0 blocks
==15903== possibly lost: 0 bytes in 0 blocks
百萬感謝詳細的解釋。對於問題2,別人在另一個論壇上告訴我,每當我初始化一個全局變量時,默認情況下它初始化爲NULL,這就是爲什麼我沒有明確初始化它。 – tadm123