OAIP_Mirror/lab26/Sources/DictHash.c

//
// Ðåàëèçàöèÿ ñëîâàðÿ íà õýøå
// 
#define _CRT_SECURE_NO_WARNINGS
#include <string.h>
#include <stdlib.h>
#include "Dict.h"



#define MAX_HASH 13267

struct Node {
	char* word;
	struct Node* next;
};

// Ìàññèâ ñïèñêîâ
struct Node* first[MAX_HASH];

// Âû÷èñëåíèå õýøà äëÿ ñòðîêè word
int hash(char* word) {
	unsigned long hash_value = 0;
	int i = 0;
	while (word[i] != '\0') {
		hash_value = 31 * hash_value + ((unsigned)(word[i]));
		i++;
	}
	return hash_value % MAX_HASH;
}



/* INSERT – äîáàâëÿåò ýëåìåíò â ìíîæåñòâî.
Ìíîæåñòâî – ñîäåðæèò òîëüêî óíèêàëüíûå ýëåìåíòû.
Ïðè ïîâòîðíîì äîáàâëåíèè ýëåìåíòà â ìíîæåñòâî, ìíîæåñòâî íå èçìåíÿåòñÿ. 
Íåò çàùèòû îò äâîéíîãî âêëþ÷åíèÿ */
void Insert(char* word) {
	struct Node* newNode = (struct Node*)malloc(sizeof(struct Node));

	int hash_value = hash(word);

	newNode->next = first[hash_value];
	newNode->word = (char*)calloc(strlen(word) + 1, sizeof(char));
	strcpy(newNode->word, word);
	first[hash_value] = newNode;
}


/* MEMBER – ñîîáùàåò, ÿâëÿåòñÿ ëè óêàçàííûé ýëåìåíò ÷ëåíîì äàííîãî ìíîæåñòâà èëè íåò. */
int  Member(char* word) {
	int hash_value = hash(word);

	struct Node* ptr = first[hash_value];
	while (ptr != NULL) {
		if (strcmp(ptr->word, word) == 0) {
			return 1;
		}
		ptr = ptr->next;
	}
	return 0;
}



/* CREATE - ñîçäàåò ñëîâàðü.
Âûçûâàåòñÿ ïåðåä íà÷àëîì èñïîëüçîâàíèÿ ñëîâàðÿ. */
void Create() {
	for (int i = 0; i < MAX_HASH; i++)
		first[i] = NULL;
}

/* DESTROY - óíè÷òîæàåò ñëîâàðü.
Âûçûâàåòñÿ ïîñëå îêîí÷àíèÿ èñïîëüçîâàíèÿ ñëîâàðÿ. */
void Destroy() {
	for (int i = 0; i < MAX_HASH; i++) {

		while (first[i] != NULL) {
			struct Node* delNode = first[i];
			first[i] = first[i]->next;

			free(delNode->word);
			free(delNode);
		}
	}
}