Queue

#include <stdio.h>
#include <string.h>
#define QUESIZ 5

void enqueue(char*,int*,int*,char);
char dequeue(char*,int*,int*);
void printQueue(char*,int*,int*);        // 큐 내용 출력

void main(){

        char queue[QUESIZ+1];                // 큐
        int fr=0, rr=0;                        // 큐 포인터 
  
        enqueue(queue,&fr,&rr,'2');
        //printf("<%s>\n",queue);       
        enqueue(queue,&fr,&rr,'0');
        enqueue(queue,&fr,&rr,'0');
        enqueue(queue,&fr,&rr,'6');
        enqueue(queue,&fr,&rr,'5');
        printf("\n");
        printQueue(queue,&fr,&rr);        // 큐 내용 출력
        printf("------------\n");
       
        dequeue(queue,&fr,&rr);
        dequeue(queue,&fr,&rr);
        dequeue(queue,&fr,&rr);
        dequeue(queue,&fr,&rr);
        dequeue(queue,&fr,&rr);

       
        enqueue(queue,&fr,&rr,'1');
        printQueue(queue,&fr,&rr);        // 큐 내용 출력
       
        enqueue(queue,&fr,&rr,'2');
        printQueue(queue,&fr,&rr);        // 큐 내용 출력
       
        dequeue(queue,&fr,&rr);
        enqueue(queue,&fr,&rr,'3');
        printQueue(queue,&fr,&rr);        // 큐 내용 출력
       
        enqueue(queue,&fr,&rr,'4');
        printQueue(queue,&fr,&rr);        // 큐 내용 출력
       
        printf("\n\n");

}

int modAdd(int a){

        return (a+1) % (QUESIZ+1);
}

void enqueue(char *queue, int *fr, int *rr, char data){
       
        if(*fr == modAdd(*rr)){                        //[예외처리]Queue가 가득차면
                printf("queue is full!\n");        //error 메세지       
                return;
        }
       
        printf("enuque[%c]!\n",data);
        queue[*rr] = data;
        *rr = modAdd(*rr);

        printf("<%s>\n",queue);       
}

char dequeue(char *queue, int *fr, int *rr){

        char data;
        if(*fr == *rr){
                printf("queue is empty!\n");
                return 0;
        }
       
        data = queue[*fr];
        *fr = modAdd(*fr);

        printf("\ndelete[%c]!\n",data);
        printQueue(queue,fr,rr);       
        return data;
}

void printQueue(char *queue, int *fr, int *rr){                // 큐에 들어 있는 데이타를 모두 출력
       
        int i = *fr;
       
        if(*fr == *rr){
                printf("queue is empty!\n");
                return;
        }else{
                printf("queue = ");
        }
       
        while(*rr != i){
                printf("[%c] ", queue[i]);
                i = modAdd(i);
        }
        printf("\n");
}