lab4a

lab4a.c

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

#define SIZE 3

typedef struct Item item;
typedef struct database db;
typedef struct key_dimension kdim;
struct Item {
	int key[2];
	char *info;
};
struct key_dimension {
	item *ip[SIZE];
};
struct database {
	kdim dim[2];
	int len;
};

char **get_command(void);
void add_item(int key1, int key2, char* info);
void delete_item(int key, int dimension);
int find_item(int key, int dimension);
void show_table(void);
int hash(int key, int iter);
char *getstr(void);

db table; // создание глобальной таблицы
item *deleted; // элемент  - флаг удаления

int main(void) {
	bool exit = false; 
	char **args; // аргументы функции
	char *check;
	int k1, k2, pos;
	table.len = 0;
	deleted = (item *)malloc(sizeof(item));
	printf("Welcome to Lab 4. The following options are now available: \n Add Item - add [key1] [key2] [info] \n Delete Item - delete [key] [dimension] \n Find Item - find [key] [dimension] \n List Items - show \n Exit - exit \n");
	while(!exit) {
		printf("-->$ ");
		args = get_command();
		if (args[1] != NULL){
			k1 = (int)strtol(args[1], &check, 10);
			if (check-args[1] != strlen(args[1])){
				printf("Invalid arguments for key1. Please write your command using only 1 whitespace. \n");
				continue;
			}
		}
		if (args[2] != NULL){
			k2 = (int)strtol(args[2], &check, 10);
			if (check - args[2] != strlen(args[2])) {
				printf("Invalid arguments for key2/dimension. Please write your command using only 1 whitespace. \n");
				continue;
			}
		}
		if (strcmp(args[0], "add") == 0) {
			add_item(k1, k2, args[3]);
		}
		else if (strcmp(args[0], "delete") == 0) {
			delete_item(k1, k2);
		}
		else if (strcmp(args[0], "find") == 0) {
			pos = find_item(k1, k2);
			if (pos != -1)
				printf("ITEM: \n key1: %d \n key2: %d \n info: %s \n", table.dim[k2-1].ip[pos]->key[0], table.dim[k2-1].ip[pos]->key[1], table.dim[k2-1].ip[pos]->info);
			else
				printf("Specific item not found. \n");
		}
		else if (strcmp(args[0], "show") == 0) {
			show_table();
		}
		else if (strcmp(args[0], "exit") == 0) {
			exit = true;
		}
		else {
			perror("invalid command\n");
		}
	}
	return 0;
}

void add_item(int key1, int key2, char *info) {
	if (table.len == SIZE) {
		printf("Table is full. \n");
		return;
	}
	if (table.len != 0 && (find_item(key1, 1) != -1 || find_item(key2, 2) != -1)) {
		printf("Item with the same key already exist. \n");
		return;
	}
	table.len++;
	item *new;
	new = (item *)calloc(1,sizeof(item));
	new->key[0] = key1;
	new->key[1] = key2;
	new->info = info; // keep in heap until the end!
	int i = 0;
	while(table.dim[0].ip[hash(key1, i)] != NULL && 
		  table.dim[0].ip[hash(key1, i)] != deleted && 
		  table.dim[0].ip[hash(key1, i)]->key[0] != key1) // lishii
		i++;
	table.dim[0].ip[hash(key1, i)] = new;
	i = 0;
	while(table.dim[1].ip[hash(key2, i)] != NULL && table.dim[1].ip[hash(key2, i)] != deleted && table.dim[1].ip[hash(key2, i)]->key[1] != key2)
		i++;
	table.dim[1].ip[hash(key2, i)] = new;
	printf("Item added successfully. \n");
}

int find_item(int key, int dimension) {
	int i = 0;
	while ((i < SIZE) && 
		   (table.dim[dimension-1].ip[hash(key, i)] != NULL) && 
		   (table.dim[dimension-1].ip[hash(key, i)]->key[dimension-1] != key)) {
		i++;
	}	
	if (i == SIZE || table.dim[dimension-1].ip[hash(key, i)] == NULL)
		return -1;
	else
		return hash(key, i);
}

void delete_item(int key, int dimension) {
	int pos = find_item(key, dimension);
	if (pos == -1){
		printf("Specefic item doesn't exist. \n");
	}
	else {
		int pos2 = find_item(table.dim[dimension - 1].ip[pos]->key[dimension % 2], 3 - dimension);
		free(table.dim[dimension-1].ip[pos]);
		table.dim[dimension - 1].ip[pos] = deleted;
		table.dim[dimension % 2].ip[pos2] = deleted;
		table.len--;
		printf("Item deleted successfully. \n");
	}
}

void show_table(void) {
	int n = 0;
	printf("%8s|%12s|%12s| Info \n", "#", "Key 1", "Key 2");
	for(int i = 0; i < SIZE; i++) {
		if (table.dim[0].ip[i] != NULL && table.dim[0].ip[i] != deleted) {
			printf("%8d|", n++);
			printf("%12d|",table.dim[0].ip[i]->key[0]);
			printf("%12d|",table.dim[0].ip[i]->key[1]);
			if (strlen(table.dim[0].ip[i]->info) <= 50)
				printf("%s\n",table.dim[0].ip[i]->info);
			else
				printf("%45s<...>\n",table.dim[0].ip[i]->info);
		}
	}
}
char **get_command(void) {
	char *buf = getstr();
	char **args = (char **)calloc(4, sizeof(char *));
	int i = 0;
	int len = strlen(buf);
	bool end = false;
	while (buf[i] == ' ' || buf[i] == '\t') {
		if (i == len)
			perror("no command was found");
		i++;
	}
	for (int j = 0; j < 3; j++) {
		args[j] = buf + i;
		while (buf[i] != ' ') {
			if (i == len){
				end = true;
				break;
			}
			i++;
		}
		if (end)
			break;
		buf[i++] = '\0';
		while (buf[i] == ' ' || buf[i] == '\t') {
			if (i == len) {
				end = true;
				break;
			}
			i++;
		}
		if (end)
			break;
	}
	if (!end)
		args[3] = buf + i;
	if (strcmp(args[0], "add") == 0 && args[3] == NULL) {
		perror("invalid arguments for command \" add \"\n");
		args[0] = "error";
	}
	else if (strcmp(args[0], "delete") == 0 && args[2] == NULL){
		perror("invalid arguments for command \" delete \"\n");
		args[0] = "error";
	}
	else if (strcmp(args[0], "find") == 0 && args[2] == NULL){
		perror("invalid arguments for command \" find \"\n");
		args[0] = "error";
	}
	return args;
}

int hash(int key, int iter) {
	return ((abs(key) + iter) % SIZE);
}

char *getstr(void) {
	char *ptr = (char *)calloc(1, sizeof(char *));
	char buf[81];
	int n, len = 0;
	do {
		n = scanf("%80[^\n]", buf);
		if (n < 0) {
			free(ptr);
			ptr = NULL;
			continue;
		}
		if (n == 0) {
			scanf("%*c");
		}
		else {
			len += strlen(buf);
			ptr = (char *)realloc(ptr, (len + 1) * sizeof(char));
			strcat(ptr, buf);
		}
	} while (n > 0);
	return ptr;
}