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queue.c
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queue.c
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#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "queue.h"
int createQ(Queue *q){
Node *n;
if((n=malloc(sizeof(Node)))==NULL){
fprintf(stderr,"Error: no enough memory");
return -1;
}
n->next=NULL;
strcpy(n->info,"FRONT");
q->back=n;
q->front=n;
return 0;
}
int emptyQ(Queue *q){
if(q->front==q->back){
return 0;
}
else{
return -1;
}
}
int enqueue(Queue *q, char info[100]){
Node * n;
if((n=malloc(sizeof(Node)))==NULL){
fprintf(stderr,"Error: no enough memory");
return -1;
}
n->next=NULL;
strcpy(n->info,info);
q->back->next=n;
q->back=n;
return 0;
}
Node * dequeue(Queue *q){
Node * n;
if(emptyQ(q)==0){
fprintf(stderr,"Error: queue empty");
}
n=q->front->next;
q->front->next=q->front->next->next;
if(q->front->next==NULL){
q->back=q->front;
}
return n;
}