/* NOTE: Your program should not reference the internals of these
 * structures. That is, it should treat the structures' fields as "private."
 * Instead, it should use the provided functions. */
struct hash_entry {
    char *key;
    void *value;
    struct hash_entry *next;
};

struct hash_table {
    int table_size;
    struct hash_entry **table;
    int size;
};

/* Allocates and returns a hash_table structure with the table sized as
 * indicated in the parameter. */
struct hash_table* hash_create(int table_size);

/* Places a key-value association into the table, returning NULL
 * if the key was not previously in the table or the previous value
 * associated with the key if the key was already present. */
void* hash_put(struct hash_table *table, char *key, void *value);

/* Returns the value associated with the given key in the table,
 * or NULL if the key is not present in the table. */
void* hash_get(struct hash_table *table, char *key);

/* Frees all memory allocated for this hash table. This does not
 * include any memory referenced by the keys or values. */
void hash_free(struct hash_table *table);