Initial commit

Makefile

+CC = gcc
+CCFLAGS = -g -Wall -Wextra -pedantic -fsanitize=address -fsanitize=leak
+
+hashmap.o: hashmap.c hashmap.h
+	$(CC) $(CCFLAGS) -c $< -o $@
+main.o: main.c
+	$(CC) $(CCFLAGS) -c $< -o $@
+
+contacts_database: main.o hashmap.o
+	$(CC) $(CCFLAGS) -o contacts_database main.o hashmap.o
+
+clean:
+	rm -f *.o contacts_database

hashmap.c

+#include "hashmap.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct hm_t {
+    struct entry_t **entries;
+    int length;
+};
+
+struct entry_t {
+    char *key;
+    char *value;
+    struct entry_t *next;
+};
+
+entry_t *hm_get_entry(const hm_t *const hm, const char *const key);
+entry_t *hm_get_entry_before(const hm_t *const hm, entry_t *entry);
+
+hm_t *hm_create(unsigned int length) {
+    hm_t *hm = (hm_t *)malloc(sizeof(hm_t));
+    hm->length = length;
+    hm->entries = (entry_t **)malloc(sizeof(entry_t *) * hm->length);
+
+    for (int i = 0; i < hm->length; i += 1) {
+        hm->entries[i] = NULL;
+    }
+
+    return hm;
+}
+
+void hm_destroy(hm_t **hm) {
+    for (int i = 0; i < (*hm)->length; i += 1) {
+        entry_t *iterator = (*hm)->entries[i];
+
+        while (iterator != NULL) {
+            entry_t *tmp = iterator;
+            iterator = iterator->next;
+            free(tmp->key);
+            free(tmp->value);
+            free(tmp);
+        }
+    }
+
+    free((*hm)->entries);
+    free(*hm);
+    *hm = NULL;
+}
+
+int hash(hm_t *hm, const char *const key) {
+    int hash_value = 0;
+
+    for (int i = 0; i < (int)strlen(key); i += 1) {
+        hash_value = 43 * hash_value + key[i];
+    }
+
+    return hash_value % hm->length;
+}
+
+hm_t *hm_set(hm_t *hm, const char *const key, const char *const value) {
+    entry_t *entry = hm_get_entry(hm, key);
+
+    if (entry != NULL) {
+        entry->value = (char *)value;
+        return hm;
+    }
+
+    int index = hash(hm, key);
+
+    entry_t *new_entry = (entry_t *)malloc(sizeof(entry_t));
+    new_entry->key = (char *)key;
+    new_entry->value = (char *)value;
+    new_entry->next = NULL;
+
+    if (hm->entries[index] == NULL) {
+        hm->entries[index] = new_entry;
+    } else {
+        entry_t *iterator = hm->entries[index];
+
+        while (iterator->next != NULL) {
+            iterator = iterator->next;
+        }
+
+        iterator->next = new_entry;
+    }
+
+    return hm;
+}
+
+entry_t *hm_get_entry(const hm_t *const hm, const char *const key) {
+    int index = hash((hm_t *)hm, key);
+    entry_t *iterator = hm->entries[index];
+
+    while (iterator != NULL && strcmp(iterator->key, key) != 0) {
+        iterator = iterator->next;
+    }
+
+    return iterator;
+}
+
+entry_t *hm_get_entry_before(const hm_t *const hm, entry_t *entry) {
+    int index = hash((hm_t *)hm, entry->key);
+    entry_t *iterator = hm->entries[index];
+
+    if (iterator == entry) {
+        return NULL;
+    }
+
+    while (iterator->next != entry) {
+        iterator = iterator->next;
+    }
+
+    return iterator;
+}
+
+char *hm_get(const hm_t *const hm, const char *const key) {
+    entry_t *entry = hm_get_entry(hm, key);
+
+    if (entry == NULL) {
+        return NULL;
+    }
+
+    return entry->value;
+}
+
+char *hm_rm(hm_t *hm, const char *const key) {
+    entry_t *entry = hm_get_entry(hm, key);
+
+    if (entry == NULL) {
+        return NULL;
+    }
+
+    entry_t *entry_before = hm_get_entry_before(hm, entry);
+
+    if (entry_before == NULL) {
+        int index = hash(hm, key);
+        hm->entries[index] = hm->entries[index]->next;
+    } else {
+        entry_before->next = entry_before->next->next;
+    }
+
+    char *value = entry->value;
+    free(entry);
+    return value;
+}
+
+char *hm_to_str(const hm_t *const hm) {
+    char *str = (char *)malloc(sizeof(char) * 100000);
+    str[0] = '\0';
+
+    for (int i = 0; i < hm->length; i += 1) {
+        char header[100];
+        sprintf(header, "%d: ", i);
+        strcat(str, header);
+
+        entry_t *iterator = hm->entries[i];
+
+        while (iterator != NULL) {
+            strcat(str, "(");
+            strcat(str, iterator->key);
+            strcat(str, ": ");
+            strcat(str, iterator->value);
+            strcat(str, ")");
+            iterator = iterator->next;
+
+            if (iterator != NULL) {
+                strcat(str, ", ");
+            }
+        }
+
+        strcat(str, "\n");
+    }
+
+    return str;
+}
+
+void hm_print(const hm_t *const hm) {
+    char *str = hm_to_str(hm);
+    printf("%s", str);
+    free(str);
+}

hashmap.h

+#ifndef HASHMAP_H
+#define HASHMAP_H
+
+typedef struct hm_t hm_t;
+typedef struct entry_t entry_t;
+
+hm_t *hm_create(unsigned int length);
+void hm_destroy(hm_t **hm);
+hm_t *hm_set(hm_t *hm, const char *const key, const char *const value);
+char *hm_get(const hm_t *const hm, const char *const key);
+char *hm_rm(hm_t *hm, const char *const key);
+char *hm_to_str(const hm_t *const hm);
+void hm_print(const hm_t *const hm);
+
+#endif

main.c

+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "hashmap.h"
+
+void clear_buffer() {
+    int c;
+    while ((c = getchar()) != '\n' && c != EOF) {
+    }
+}
+
+int main() {
+    struct hm_t *hm = hm_create(2);
+
+    while (true) {
+        printf("1=exit, 2=add, 3=delete, 4=search: ");
+        int action;
+        scanf("%d", &action);
+        clear_buffer();
+
+        if (action < 1 || action > 4) {
+            printf("Invalid action!\n");
+            continue;
+        }
+
+        char key[100];
+        char value[100];
+
+        if (action == 1) {
+            break;
+        } else if (action == 2) {
+            printf("Phone Number: ");
+            scanf("%s", key);
+            clear_buffer();
+
+            printf("Name: ");
+            scanf("%s", value);
+            clear_buffer();
+
+            char *a = strdup(key);
+            char *b = strdup(value);
+            hm_set(hm, a, b);
+        } else if (action == 3) {
+            printf("Phone Number: ");
+            scanf("%s", key);
+            clear_buffer();
+
+            hm_rm(hm, key);
+        } else if (action == 4) {
+            printf("Phone Number: ");
+            scanf("%s", key);
+            clear_buffer();
+
+            char *v = hm_get(hm, key);
+            printf("Name = %s\n", v);
+        }
+    }
+
+    hm_destroy(&hm);
+    return EXIT_SUCCESS;
+}