creating function to add word into dictionary - c

Question

I want to create function that adds words into dictionary
so far i made this
void addWord(char **dictionary,int *dictionarySize,int *wordsInDictionary,char *word){
if(dictionary == NULL)
{
*dictionary = (char *)malloc(sizeof(char*)*(*dictionarySize));
}
else
{
if(*wordsInDictionary==*dictionarySize)
{
*dictionary = (char *)realloc(dictionary,sizeof(char*)*(*dictionarySize)*2);
(*dictionarySize)*=2;
}
}
dictionary[*wordsInDictionary]=word;
(*wordsInDictionary)++;
}
in main() i have
int i;
int dictSize = 1;
int wordsInDict = 0;
char *word;
char *dictionary;
dictionary=NULL;
then i want to print all words in dictionary , but here i get warning that %s is expecting char* but it is int
printf("Stats: dictsize: %d, words in dict: %d\n", dictSize,wordsInDict);
for(i=0;i<wordsInDict;i++)
{
printf("%d. %s\n",i, dictionary[i]);
}
it also gives me errors when i try to add words
i use this call to add words
addWord(&dictionary,&dictSize,&wordsInDict,word);

Answer 1

In your addWord function, dictionary will never be NULL.
And that's only the start of your problems. Because you want dictionary to be an array of arrays, which mean you need to declare it as a pointer to a pointer (if you want it to be dynamic). However, you declare it as just a (single) pointer. It's in the main function (or where ever you declare it originally) that you need to declare it as a pointer to a pointer. And you need to initialize it, or it will have an indeterminate value and using it in any way other than initializing it will lead to undefined behavior.
That means your addWord function should take a pointer to a pointer to a pointer, i.e. one more level of indirection. And you need to use the dereference operator to get the original pointer to pointer.
So the addWord function should start like e.g.
void addWord(char ***dictionary, int *dictionarySize, int *wordsInDictionary,char *word){
if(*dictionary == NULL)
{
*dictionary = malloc(sizeof(char*) * (*dictionarySize));
}
...
}
Also note that I don't cast the return of malloc.
Also note that realloc can fail, and then will return NULL, so if you assign the return to the same pointer you reallocate you will loose the original pointer. Always use a temporary pointer for the return-value of realloc and only assign to the real pointer after checking that the reallocation succeeded.

Answer 2

I suggest that you put together the members of the dictionary in one as a structure, rather than having individually.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct dictionary {
char **words;//array of char *
int size;
int numOfWords;
} Dictionary;
Dictionary *D_new(void){
Dictionary *dic = malloc(sizeof(*dic));
if(dic){
dic->size = 16;//initial size
dic->words = malloc(dic->size * sizeof(*dic->words));//check omitted
dic->numOfWords = 0;
}
return dic;
}
void D_drop(Dictionary *dic){
int i;
for(i=0;i<dic->numOfWords; ++i)
free(dic->words[i]);
free(dic->words);
free(dic);
}
void addWord(Dictionary *dic, const char *word){
if(dic == NULL){
return ;
}
if(dic->numOfWords == dic->size){
dic->words = realloc(dic->words, sizeof(*dic->words)*(dic->size*=2));//check omitted
}
dic->words[dic->numOfWords++]=strdup(word);//make copy
}
int main(void){
int i;
Dictionary *dictionary = D_new();
addWord(dictionary, "apple");
addWord(dictionary, "banana");
addWord(dictionary, "melon");
printf("Stats: dictsize: %d, words in dict: %d\n",
dictionary->size, dictionary->numOfWords);
for(i=0;i<dictionary->numOfWords;i++){
printf("%d. %s\n", i, dictionary->words[i]);
}
D_drop(dictionary);
return 0;
}