C++ retrieve array via returned array pointer .Retrieve array via returned pointer one by one.

#include <iostream>
#include <uuid/uuid.h>
#include <pthread.h>

using namespace std;

void retrieveUuid(char *uuidValue);
struct BookStruct
{
    int BookId;
    char *BookName;
    char *BookTitle;
};

static int num=1;

struct BookStruct * retrieveArr();
void retrieveStructArr();

int main()
{
    retrieveStructArr();
    return 0;
}

void retrieveStructArr()
{ 
    struct BookStruct *p;
    p=retrieveArr();
    for(int i=0;i<100;i++)
    {
        printf("Index=%d,Id=%d,Name=%s,Title=%s\n",i,(p+i)->BookId,(p+i)->BookName,(p+i)->BookTitle);
        free((p+i)->BookName);
        free((p+i)->BookTitle);
    } 
    printf("Finished in retrieveStructArr()!\n");    
}

struct BookStruct * retrieveArr()
{
    static struct BookStruct arr[100];
    for(int i=0;i<100;i++)
    {
         arr[i].BookId=num*num*num*num;
         ++num;
         arr[i].BookName=(char*)malloc(40);
         retrieveUuid(arr[i].BookName);
         arr[i].BookTitle=(char*)malloc(40);
         retrieveUuid(arr[i].BookTitle);
    }
    struct BookStruct *structP;
    structP=&arr[0];
    return structP;
}

void retrieveUuid(char *uuidValue)
{
    uuid_t newUUID;
    uuid_generate(newUUID);
    uuid_unparse(newUUID, uuidValue);
}

Compile as below command

g++ -g -std=c++2a -I. h1.cpp -o h1 -luuid -lpthread

#include <iostream>
#include <uuid/uuid.h>
#include <pthread.h>

using namespace std;

void retrieveUuid(char *uuidValue);

struct BookStruct
{
    int BookId;
    char *BookName;
    char *BookTitle;
};

static int num=1;

void retrivedSingle(struct BookStruct *structP);
void array6();

int main()
{
    array6();
    return 0;
}

void array6()
{
    struct BookStruct arr[100];
    for(int i=0;i<100;i++)
    {
        retrivedSingle(&arr[i]);
    }

    for(int i=0;i<100;i++)
    {
        printf("Index=%d,Id=%d,Name=%s,Title=%s\n",i,arr[i].BookId,arr[i].BookName,arr[i].BookTitle);
        free(arr[i].BookName);
        free(arr[i].BookTitle);
    }

    printf("\nFinished in array6()\n");
}

void retrivedSingle(struct BookStruct *structP)
{
    (*structP).BookId=num*num*num*num;
    ++num;
    (*structP).BookName=(char*)malloc(40);
    (*structP).BookTitle=(char*)malloc(40);
    retrieveUuid((*structP).BookName);
    retrieveUuid((*structP).BookTitle);
}


void retrieveUuid(char *uuidValue)
{
    uuid_t newUUID;
    uuid_generate(newUUID);
    uuid_unparse(newUUID, uuidValue);
}

Compile as below:

g++ -g -std=c++2a -I. h1.cpp -o h1 -luuid -lpthread