ramen.c

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

#define TRUE  1
#define FALSE 0
#define show_shop printf("%s\n", dump_shop(shop))

enum CustomerState { LEAVE, WAIT, EAT, REST };

struct Seat {
	enum CustomerState state;
	struct Seat *left;
};

struct RarmenShop {
	int seat_size;
	struct Seat* first;
};

struct Seat* alloc_seat() {
	return (struct Seat *)malloc(sizeof(struct Seat));
}

struct Seat * create_seats(int seat_size) {
	int i;
	struct Seat* first;
	struct Seat* current = NULL;

	for(i =0; i < seat_size; i++) {
		if (current == NULL) {
			current = alloc_seat();
			memset(current, 0, sizeof(struct Seat));
			first = current;
		} else {
			current->left = alloc_seat();
			current = current->left;
		}
	}

	current->left = first;
	return first;
}

struct RarmenShop* create_shop(int seat_size) {
	struct RarmenShop* shop = (struct RarmenShop *)malloc(sizeof(struct RarmenShop));
	memset(shop, 0, sizeof(struct RarmenShop));

	shop->seat_size = seat_size;
	shop->first = create_seats(seat_size);
	return shop;
}

void close_shop(struct RarmenShop* shop ) {
	struct Seat* current = shop->first;
	struct Seat* next;

	do {
		next = current->left;
		free(current);
		current = next;
	} while(current != shop->first);
	free(shop);
}

int is_empty_seat(const struct Seat* seat) {
	return seat->state == LEAVE;
}

char* dump_shop(struct RarmenShop* shop) {
	char* result = (char *)malloc(sizeof(char) * shop->seat_size + 1);
	struct Seat* current = shop->first;
	int i;

	for(i = 0; i < shop->seat_size; i++) {
		if (is_empty_seat(current)) {
			result[i] = '0';
		} else {
			result[i] = '1';
		}
		current = current->left;
	}
	result[i] = '\0';

	return result;
}

void leav_seat(struct Seat* seat) {
	seat->state = LEAVE;
}

void sitdown(struct Seat* seat) {
	seat->state = WAIT;
}

void change_state(struct Seat* seat) {
	switch(seat->state) {
		case WAIT:
			seat->state = EAT;
			break;
		case EAT:
			seat->state = REST;
			break;
		case REST:
			leav_seat(seat);
			break;
		default:
			break;
	}
}

void change_shop_state(struct RarmenShop* shop) {
	struct Seat* current = shop->first;
	do {
		change_state(current);
		current = current->left;
	} while(current != shop->first);
}

int can_sitdown(struct Seat* seat, int custormer_size) {
	int i;
	struct Seat* current = seat;
	for (i = 0; i < custormer_size; i++) {
		if(is_empty_seat(current)) {
			current = current->left;
		} else {
			return FALSE;
		}
	}
	return TRUE;
}

void sitdown_customer(struct Seat* seat, int custormer_size) {
	int i;
	struct Seat* current = seat;

	for (i = 0; i < custormer_size; i++) {
		sitdown(current);
		current = current->left;
	}
}

int guide_customer(struct RarmenShop* shop, int custormer_size) {
	struct Seat* current = shop->first;
	do {
		if (can_sitdown(current, custormer_size)) {
			sitdown_customer(current, custormer_size);
			return TRUE;
		}
		current = current->left;
	} while(current != shop->first);

	return FALSE;
}

void test(char* customer, char* expect) {
	struct RarmenShop* shop = create_shop(8);
	int group_size = strlen(customer);
	int i;
	char* result;

	for(i = 0; i < group_size; i++) {
		do {
			change_shop_state(shop);
		} while(!guide_customer(shop, (int)customer[i] - 48));
	}
	result = dump_shop(shop);

	if(!strcmp(result, expect)) {
		printf("true  : ");
	} else {
		printf("false : ");
	}
	printf("%s,%s,%s\n", customer, result, expect);

	close_shop(shop);
	free(result);
}

int main() {
	test("3316", "11111110");
	test("3342153", "11111111");
	test("8", "11111111");
	test("232624", "11110110");
	test("1", "10000000");
	test("224673432", "11111000");
	test("123464334", "11111110");
	test("44372332", "11111111");
	test("2344", "11111111");
	test("6448476233", "11111100");
	test("4345174644", "11111111");
	test("77743", "11111110");
	test("2136524281", "10000000");
	test("344373", "11100000");
	test("434226", "11111111");
	test("7433223", "11111110");
	test("2246534", "11110111");
	test("634", "11111110");
	test("2222", "11111100");
	test("2442343238", "11111111");
	test("7243344", "11111111");
	test("26147234", "10111111");
	test("34424", "10011111");
	test("6334", "11011111");
	test("3828342", "11011110");
	test("4431", "11110000");
	test("2843212125", "11111111");
	test("333336482", "11000000");
	test("374", "11110000");
	test("4382333", "11100111");
	return 0;
}