Okay I am lost. I have to do simple implementation of insertion and deletion of queue. The Q.h file was given to me and I have to work on that to build my code. I probably have a gazillion mistakes but please guide me. Here is my code. It is separate compilation, so:
Q.h (HEADER FILE)
Q.c FILE:Code:struct Queue_struct; typedef struct Queue_struct Q_type; /* Allocate a new Queue and initialize it to be empty. */ Q_type *Q_new(); /* Deallocate a Queue and free the memory */ void Q_free(Q_type *); /* Print the Queue in an attractive fashion */ void Q_print (Q_type *); /* error codes for errorflag returned by Q_add and Q_delete */ #define ERROR_FULL_QUEUE 0 #define ERROR_EMPTY_QUEUE -1 #define EVERYTHING_OK 1 /* add an item at the end of the Queue */ void Q_add(Q_type *, int, int *errorflag); /* remove an item from the front of the Queue */ int Q_delete(Q_type *, int *errorflag); /* note errorflag is passed by reference so values can change */
main.c FILE:Code:#include <stdio.h> #include <stdlib.h> #include .Q.h" /********************************************************* Implementation of the Queue ADT using a fixed size array. *********************************************************/ /* Queue size must be an array of size 10 */ #define Q_MAX_SIZE 10 struct Q_struct { /* Pointer to the array of list elements. Each element is a generic pointer. */ void **elements; /* The number of elements in the list. */ int length; }; static void _list_extend(Q_type *Q) { if (Q->elements == NULL) { Q->elements = malloc(sizeof(void*)); } else { Q->elements = realloc(Q->elements, sizeof(void*) * (Q->length + 1)); } if (Q->elements == NULL) { fprintf(stderr, "list_insert: out of memory.\n"); exit(1); } } Q_type *Qnew() { Q_type *Q; Q = (Q_type *)malloc(sizeof(Q_type)); Q->elements = NULL; Q->length = 0; return Q; } void Q_insert(Q_type *Q, void *data) { int i; _list_extend(Q); for (i = Q->length - 1; i >= 0; i--) { Q->elements[i + 1] = Q->elements[i]; } Q->elements[0] = data; (Q->length)++; }
Code:#include <string.h> #include <stdio.h> #include <stdlib.h> #include "Q.h" /* Queue header file */ typedef struct student { // char lastName[16]; int id; // float gpa; // char major[5]; } student; void showcommands() { printf("Queue Processing Commands:\n"); printf("==========================\n"); printf("n : \n"); printf("p : \n"); printf("a : \n"); printf("d : \n"); printf("v : \n"); printf("e : \n"); printf("f : \n"); } main(void) { Q_type *myQ; myQ = Q_new(); char command; // store current command int errorcode; // possible error code int value; // value to be inserted or returned float avg; // average of queue values show_commands(); printf("Queue command? "); scanf("%c", command); while (command != 'q') { switch (command) { case 'n': free(myQ); myQ = Q_new(); break; case 'p': Q_print(myQ); break; case 'a': printf("Enter value to insert: "); scanf("%d", value); Q_add(myQ, value, &errorflag); if (errorflag == ERROR_FULL_QUEUE) printf("Queue full -- insert failed.\n"); break; case 'd': value = Q_delete(myQ, &errorflag); if (errorflag != ERROR_EMPTY_QUEUE) printf("Removed value [%d]\n",value); else printf("Queue empty -- delete failed.\n"); break; default: printf("Command not recognized\n"); show_commands(); } printf("Queue command? "); scanf("%c",command); } Q_free (myQ); return 0; }
