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

typedef struct counter *Counter;

/** Creates a new empty counter */
Counter CounterNew(void);

/** Free memory used by counter */
void CounterFree(Counter c);

/** Add one to the count of an item */
void CounterAdd(Counter c, int item);

/** Get the count of an item */
int CounterGet(Counter c, int item);