Trie Implementation with c++

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include<malloc.h>
#define ARRAY_SIZE(a) sizeof(a)/sizeof(a[0])

// Alphabet size (# of symbols)
#define ALPHABET_SIZE (26)
// Converts key current character into index//tabdile kelide charachtere jari be index
// use only 'a' through 'z' and lower case // faghat az a ta z va horofe kochak estefade mikonad
#define CHAR_TO_INDEX(c) ((int)c - (int)'a')
static int test;
// trie node
typedef struct trie_node trie_node_t;
struct trie_node
{
    int value;
    trie_node_t *children[ALPHABET_SIZE];
};

// trie ADT
typedef struct trie trie_t;
struct trie
{
    trie_node_t *root;
    int count;
};

// Returns new trie node (initialized to NULLs)//gereye derakhte jadid ra bar migardanad ( meghdar dehie avalie ba Null)
trie_node_t *getNode(void)
{
    trie_node_t *pNode = NULL;

    pNode = (trie_node_t *)malloc(sizeof(trie_node_t));//meghdare hafeze dar tire_node_t ra bar hasbe byte ba estefade az malloc be barname takhsis midahad,va noe in eshare gar az node node_trie_t mibashad//1 Argoman (meghdar fazaye morede niaz) ra bar migardanad ((meghdar fazaye moshakhasi ra be barname bar migardanad))
    //size of => tole motaghayer va ya noe motaghayer ra bar hasbe byte mitavan be dast avard.
    if(!pNode)//hich hafezei be pnode takhsis dade nashode
    {
        printf("\n\n takhsise faza anjam nashod !! ");
        return NULL;
    }
    if( pNode )
    {
        int i;
        pNode->value = 0;

        for(i = 0; i < ALPHABET_SIZE; i++)
        {
            pNode->children[i] = NULL;
        }
    }

    return pNode;
}

// Initializes trie (root is dummy node)
void initialize(trie_t *pTrie) // methode meghdar dehie avalie az noe void ba 1 meghdar az noe eshare gar be name pTrie.
{
    pTrie->root = getNode();
    pTrie->count = 0;
}

// If not present, inserts key into trie
// If the key is prefix of trie node, just marks leaf node
void insert(trie_t *pTrie, char key[])
{
    int level;
    int length = strlen(key);//key= arayei az charechter ha, tole key ra dar lengh mirizim
    int index;
    trie_node_t *pCrawl;

    pTrie->count++;
    pCrawl = pTrie->root;

    for( level = 0; level < length; level++ )
    {
        index = CHAR_TO_INDEX(key[level]);
        if( !pCrawl->children[index] )
        {
            pCrawl->children[index] = getNode();
        }

        pCrawl = pCrawl->children[index];
    }

    // mark last node as leaf//alamat gozarie akharie gereh be onvane barg
    pCrawl->value = pTrie->count;
}

// Returns non zero, if key presents in trie
int search(trie_t *pTrie, char key[])
{
    int level,i;
    int length = strlen(key);
    int index;
    trie_node_t *pCrawl;

    pCrawl = pTrie->root;

    for( level = 0; level < length; level++ )
    {
        index = CHAR_TO_INDEX(key[level]);

        if( !pCrawl->children[index] )
        {
            return 0;
        }

        pCrawl = pCrawl->children[index];
    }

    return (0 != pCrawl && pCrawl->value);
}
//after having the prefix traverse the sub tree of trie to fetch and print the suggestions
void traverse(trie_node_t *pCrawl, char key[],int index)
{
   int i;
   char *temp;

   if(!pCrawl)
   {

       return ;
   }
   if(pCrawl->value!=0&&pCrawl!=NULL)
   {
       printf("%s\n",key);

}
   for(i=0;i<26;i++)
   {

       temp=(char *)malloc(sizeof(char)*strlen(key)+2);
       strcpy(temp,key);
       temp[strlen(key)]=(char)(97+i);
       temp[strlen(key)+1]='&#92&#48';
       if(pCrawl->children[i]!=NULL)
       traverse(pCrawl->children[i], temp,i);


       free(temp);
}


}
//travel down the trie upto the prefix and then look for suggestion using traverse function
// harkat in derakht ta pishvand va sepas peyda kardane pishnehad ba estefade az tabe'e traverse
int suggestions(trie_t *pTrie, char key[]) //
{
    int level,i;
    int length = strlen(key);
    int index;
    trie_node_t *pCrawl;

    pCrawl = pTrie->root;
    if(strcmp(key,"")==0)
    {
        printf("The input is NULL!!");
        return 0;
    }

    for( level = 0; level < length; level++ )
    {
        index = CHAR_TO_INDEX(key[level]);

        if( !pCrawl->children[index] )
        {

        printf("Prefix is not present");
            return 0;
        }

        pCrawl = pCrawl->children[index];
    }
traverse(pCrawl, key,index);
}
//checks whether the string contains lowercase only
/*int check(char key[])
{
int i,status;
i=0;
status=-1;
while(key[i]!='&#92&#48')
    {
        if(!(key[i]<='z'&&key[i]>='a'))
        {   status=0;
            return status;
        }
        i++;
    }
status =1;
return 1;
}*/


// Driver
int main()
{

    int i,status,prompt;
    char inputString[30];
    prompt=1;
    trie_t trie;
    initialize(&trie);
while(prompt!='4')
{
    printf("\nPress 1 to insert a string into the database\nPress 2 to look for suggestions\nPress 3 to search a string\nPress 4 to exit\n");
    scanf("%d",&prompt);
    switch(prompt)
    {
        case 1 : printf("\nPlease enter the string\n");
                   scanf("%s",inputString);
           if(strcmp(inputString,"")==0)
            {
                printf("Empty strings are not allowed");
                break;
            }
    /*   if(check(inputString)==0)
            {
                printf("\nSorry Only lower case alphabets are allowed !!\n");
                break;
            }*/
                   insert(&trie, inputString);
                   strcpy(inputString,"");
                   break;
        case 2 : printf("\nPlease enter the pattern\n");
                   scanf("%s",inputString);
           if(strcmp(inputString,"")==0)
            {
                printf("Empty strings are not allowed");
                break;
            }
         /*  if(check(inputString)==0)
            {
                printf("\nSorry Only lower case alphabets are allowed !!\n");
                break;
            }*/
           printf("\nThe patterns are ::\n");
                   suggestions(&trie,inputString);
                 //  strcpy(inputString,"");
                   break;
        case 3 : printf("\nPlease enter the string to be searched\n");
                   scanf("%s",inputString);
           if(strcmp(inputString,"")==0)
            {
                printf("Empty strings are not allowed");
                break;
            }
    /*     if(check(inputString)==0)
            {
                printf("\nSorry Only lower case alphabets are allowed !!\n");
                break;
            }*/
                   status=search(&trie,inputString);
                   strcpy(inputString,"");
            if(status==0)
                printf("\nThe string you are looking is not present in the databse\n");
            else
                printf("The string is present in the database");

                   break;

    case 4 : return 0;
        default: printf("Invalid option!!Please try again!!!!\n\n");
                 break;
    }

}

    return 0;
}