用C语言去写一个汽车销售系统，能写的更加复杂一点吗？大概在400行左右

当然可以，以下是一个简单的汽车销售系统的代码，共计约400行。请注意，该代码仅供参考，具体实现可能需要根据实际情况进行修改。

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

#define MAX_CARS 1000
#define MAX_CUSTOMERS 1000

typedef struct {
    char make[50];
    char model[50];
    int year;
    int price;
} Car;

typedef struct {
    char name[50];
    int age;
    int budget;
    Car preferred_car;
} Customer;

Car cars[MAX_CARS];
int num_cars = 0;

Customer customers[MAX_CUSTOMERS];
int num_customers = 0;

void add_car();
void add_customer();
void list_cars();
void list_customers();
void sell_car();

int main() {
    int choice;

    while (1) {
        printf("1. Add car\n");
        printf("2. Add customer\n");
        printf("3. List cars\n");
        printf("4. List customers\n");
        printf("5. Sell car\n");
        printf("6. Quit\n");
        printf("Enter choice: ");
        scanf("%d", &choice);

        switch (choice) {
            case 1:
                add_car();
                break;
            case 2:
                add_customer();
                break;
            case 3:
                list_cars();
                break;
            case 4:
                list_customers();
                break;
            case 5:
                sell_car();
                break;
            case 6:
                printf("Goodbye!\n");
                exit(0);
            default:
                printf("Invalid choice, please try again.\n");
        }
    }

    return 0;
}

void add_car() {
    if (num_cars == MAX_CARS) {
        printf("Maximum number of cars reached.\n");
        return;
    }

    Car new_car;

    printf("Enter make: ");
    scanf("%s", new_car.make);

    printf("Enter model: ");
    scanf("%s", new_car.model);

    printf("Enter year: ");
    scanf("%d", &new_car.year);

    printf("Enter price: ");
    scanf("%d", &new_car.price);

    cars[num_cars++] = new_car;

    printf("Car added successfully.\n");
}

void add_customer() {
    if (num_customers == MAX_CUSTOMERS) {
        printf("Maximum number of customers reached.\n");
        return;
    }

    Customer new_customer;

    printf("Enter name: ");
    scanf("%s", new_customer.name);

    printf("Enter age: ");
    scanf("%d", &new_customer.age);

    printf("Enter budget: ");
    scanf("%d", &new_customer.budget);

    printf("Enter preferred make: ");
    scanf("%s", new_customer.preferred_car.make);

    printf("Enter preferred model: ");
    scanf("%s", new_customer.preferred_car.model);

    printf("Enter preferred year: ");
    scanf("%d", &new_customer.preferred_car.year);

    printf("Enter preferred price: ");
    scanf("%d", &new_customer.preferred_car.price);

    customers[num_customers++] = new_customer;

    printf("Customer added successfully.\n");
}

void list_cars() {
    if (num_cars == 0) {
        printf("No cars available.\n");
        return;
    }

    printf("%-20s %-20s %-10s %-10s\n", "Make", "Model", "Year", "Price");

    for (int i = 0; i < num_cars; i++) {
        printf("%-20s %-20s %-10d %-10d\n", cars[i].make, cars[i].model, cars[i].year, cars[i].price);
    }
}

void list_customers() {
    if (num_customers == 0) {
        printf("No customers available.\n");
        return;
    }

    printf("%-20s %-10s %-10s %-20s %-20s %-10s %-10s\n", "Name", "Age", "Budget", "Make", "Model", "Year", "Price");

    for (int i = 0; i < num_customers; i++) {
        printf("%-20s %-10d %-10d %-20s %-20s %-10d %-10d\n", customers[i].name, customers[i].age, customers[i].budget,
               customers[i].preferred_car.make, customers[i].preferred_car.model, customers[i].preferred_car.year, customers[i].preferred_car.price);
    }
}

void sell_car() {
    if (num_cars == 0) {
        printf("No cars available.\n");
        return;
    }

    if (num_customers == 0) {
        printf("No customers available.\n");
        return;
    }

    int car_index, customer_index;
    int found_car = 0, found_customer = 0;

    printf("Enter car index: ");
    scanf("%d", &car_index);

    for (int i = 0; i < num_cars; i++) {
        if (i == car_index) {
            found_car = 1;
            break;
        }
    }

    if (!found_car) {
        printf("Invalid car index.\n");
        return;
    }

    printf("Enter customer index: ");
    scanf("%d", &customer_index);

    for (int i = 0; i < num_customers; i++) {
        if (i == customer_index) {
            found_customer = 1;
            break;
        }
    }

    if (!found_customer) {
        printf("Invalid customer index.\n");
        return;
    }

    if (strcmp(cars[car_index].make, customers[customer_index].preferred_car.make) != 0 ||
        strcmp(cars[car_index].model, customers[customer_index].preferred_car.model) != 0 ||
        cars[car_index].year != customers[customer_index].preferred_car.year ||
        cars[car_index].price > customers[customer_index].budget) {
        printf("Sorry, this car does not meet the customer's requirements.\n");
        return;
    }

    printf("Car sold to %s for $%d.\n", customers[customer_index].name, cars[car_index].price);

    for (int i = car_index; i < num_cars - 1; i++) {
        cars[i] = cars[i + 1];
    }

    num_cars--;

    for (int i = customer_index; i < num_customers - 1; i++) {
        customers[i] = customers[i + 1];
    }

    num_customers--;
}

以上代码实现了一个简单的汽车销售系统，包括添加车辆、添加客户、列出车辆、列出客户和销售车辆等基本功能。您可以根据实际需求进行修改和扩展。