#include <stdbool.h>                                          /* queue.h */

typedef struct QueueNodeStruct {
        char data;
        struct QueueNodeStruct * nextPtr;  /* struct label necessary! */
    } QueueNode;

typedef struct {
        QueueNode * head, * tail;
    } Queue;

void printQueue( Queue * );

void initQueue(Queue * );

Queue * newQueue();

bool enqueue( Queue *, char );

bool isEmpty( Queue * );

char dequeue( Queue * );