c 环状队列

#include <stdio.h>#define maxsize 10typedef struct{ int elem[maxsize]; int front,rear;}queue;void init_queue(queue *cp){ cp->front=0; cp->rear=0;}void en_queue(queue *cp,int x){ if((cp->rear+1)%maxsize==cp->front) printf("The quequ is full!!"); else { cp->rear=(cp->rear+1)%maxsize; cp->elem[cp->rear]=x; }}int dl_queue(queue *cp){ if(cp->front==cp->rear) {printf("The queue is empty!!"); return -1; } else { cp->front=(cp->front+1)%maxsize; return(cp->elem[cp->front]); }}void print(queue *cp){ int i; for(i=cp->front+1;i<=cp->rear;i++) { printf("[%d]",cp->elem[i]); }}void main(){ int x,y; int select; queue *cp=NULL; init_queue(cp); do { printf("/n(1) Input a data"); printf("/n(2) Output a data"); printf("/n(3) Exit"); printf("/nPlease select one:"); scanf("%d",&select); switch(select) { case 1:printf("/nPlease input the data:"); scanf("%d",&x); en_queue(cp,x); printf("/nThe queue is: "); print(cp); break; case 2:y=dl_queue(cp); printf("/nThe queue is: "); print(cp); printf("/nThe putout data is %d",y); break; case 3:break; } } while(select<3); getch();}