C language Code for Assignment of Double Linked List

Below this is my code for Assignment Double Linked List with Menu

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

struct product{
char productName[101];
int quantity;
int index;
long int price;
struct product *next;
struct product *prev;
} *head = NULL, *tail = NULL, *curr;

int idx = 0;

product item(){
product in;
curr = (product*)malloc(sizeof(product));
printf("Input the product name: ");
scanf("%[^\n]", &in.productName);

printf("Input quantity of product: ");
scanf("%d%*c", &in.quantity);
idx ++;
return in;
}

void addItem(product in){
curr = (struct product*)malloc(sizeof(struct product));
*curr = in;
curr->next = curr->prev = NULL;
curr->index = idx;

if(head == NULL){
head = tail = curr;
}
else if (curr->index < head->index){
curr->next = head;
head->prev = curr;
head = curr;
curr->prev = NULL;
}
else if (curr->index >= tail->index){
tail->next = curr;
curr->prev = tail;
tail = curr;
}
else{
product *temporary = head;
while(temporary->next->index < curr->index){
temporary = temporary->next;
}
curr->next = temporary->next;
temporary->next->prev = curr;
temporary->next = curr;
curr->prev = temporary;
}
printf("Success in adding item!\n\n");
}

product* searchCodeproduct(int index){
product *search = head;
while(search != NULL){
if(search->index == index) break;
search = search->next;
}
return search;
}

void editQuantity(int index){
int newQuantity;
product *search = searchCodeproduct(index);
if(head == NULL){
printf("No data in Basket!\n\n");
}
else if(search == NULL){
printf("Invalid code product!\n\n");
}
else{
printf("Input new quantity: ");
scanf("%d*c", &newQuantity);

curr = search;
curr->quantity = newQuantity;

printf("Success edit quantity! new quantity for product %s is %d.\n\n", curr->productName, curr->quantity);
}
}

void deleteProduct(int index){
product *search = searchCodeproduct(index);
if(head == NULL){
printf("No data in Basket!\n\n");
}
else if (search == NULL){
printf("Invalid code product! Failed to delete!\n\n");
}
else{
if(head == tail){
free(search);
head = tail = NULL;
}
else if(search == head){
head = head->next;
free(search);
head->prev = NULL;
}
else if(search == tail){
tail = tail->prev;
free(search);
tail->next = NULL;
}
else{
product *temporary = head;
while(temporary != NULL && temporary != search){
temporary = temporary->next;
}
temporary->next->prev = temporary->prev;
temporary->prev->next = temporary->next;
free(temporary);
}
printf("Success removing the product from basket!\n\n");
}
}

void printAllItem(){
product *out = head;
printf("List item\n");
printf("[code - name - quantity]\n");
while(out != NULL){
printf("%d. %s - %d\n", out->index, out->productName, out->quantity);
out = out->next;
}
}

long int getRandoms() {
long int lower = 100000;
long int upper = 2000000;
    long int num = (rand() % (upper - lower + 1)) + lower;
    return num;
}

void printAllItemCheckOut(){
product *out = head;
long int sum = 0;
printf("List item\n");
printf("[code - name - quantity - price - sum]\n");
while(out != NULL){
out->price = getRandoms();
long int total = 0;
total = (out->price)*(out->quantity);
printf("%d. %s - %d - %ld -> %ld\n", out->index, out->productName, out->quantity, out->price, total);
sum = sum + total;
out = out->next;
}
printf("\n\n");
printf("Total price: %ld\n\n", sum);
}

void freeAll(){
while (head != NULL){
product *temporary = head;
head = head->next;
free(temporary);
}
idx = 0;
}

void printMenu(){
printf(" Welcome to Dreamers Market!\n");
printf("-----------------------------\n");
printf("1. Add Product to Basket\n");
printf("2. Edit Product quantity in Basket\n");
printf("3. Delete Product in Basket\n");
printf("4. Check out Product\n");
printf("5. Exit\n");
printf("\n");
printf("Input your choice: ");
}

int main(){
int menu, kuantitasBarang, inputIndex;
char namaBarang[101];
do{
printMenu();
scanf("%d%*c", &menu);

if(menu == 1){
addItem(item());
}
else if(menu == 2){
printAllItem();
inputIndex = 0;
printf("Input code product: ");
scanf("%d*c", &inputIndex);
editQuantity(inputIndex);
}
else if(menu == 3){
printAllItem();
inputIndex = 0;
printf("Input code product: ");
scanf("%d*c", &inputIndex);
deleteProduct(inputIndex);
}
else if(menu == 4){
printAllItemCheckOut();
printf("Kindness is free!\n\n");
freeAll();
}else if(menu == 5){
freeAll();
printf("Thanks for shopping! Hope you enjoy!\n");
}else{
printf("Your input is invalid. Please try again!\n");
printf("\n");
}
}while(menu != 5);

return 0;
}


For zip file of this code, please click here