1 循环数组队列

1.1 队列定义

/*
 * loop_queue.h
 *
 *  Created on: Mar 2, 2022
 *      Author: xhome.
 */

#ifndef OTHER_TASK_LOOP_QUEUE_H_
#define OTHER_TASK_LOOP_QUEUE_H_

#include <stdio.h>

#define  DATA_LEN   512

typedef struct {
	float data[DATA_LEN];
	int front;
	int rear;
	int capacity;
}loop_queue_t;

void init_loop_queue(loop_queue_t *queue, int capacity);
int full_loop_queue(loop_queue_t *queue);
int empty_loop_queue(loop_queue_t *queue);
int enter_loop_queue(loop_queue_t *queue, float dat);
int out_loop_queue(loop_queue_t *queue, float *dat);
int get_loop_queue_average(loop_queue_t * queue, float * avg);
int get_queue_rate(loop_queue_t * queue,float coef, float * rate);
int show_loop_queue(loop_queue_t * queue);


#endif /* OTHER_TASK_LOOP_QUEUE_H_ */

1.2 循环队列实现

/*
 * loop_queue.c
 *
 *  Created on: Mar 2, 2022
 *      Author: xhome.
 */

#include <stdio.h>
#include "loop_queue.h"

/**
 * capacity: The number of stored elements in the queue.
 */
void init_loop_queue(loop_queue_t *queue, int capacity)
{
	if((capacity > (DATA_LEN-1)) || (capacity < 0)){
		queue->capacity = DATA_LEN-1;
	}else{
		queue->capacity = capacity+1;
	}

	queue->front = 0;
	queue->rear = 0;
	return;
}

int full_loop_queue(loop_queue_t *queue)
{
	if(queue->front == (queue->rear+1)%(queue->capacity)){
		return 1;
	}else{
		return 0;
	}
}

int empty_loop_queue(loop_queue_t *queue)
{
	if(queue->front == queue->rear){
		return 1;
	}else{
		return 0;
	}
}

int enter_loop_queue(loop_queue_t *queue, float dat)
{
	if(full_loop_queue(queue) == 1){
		return 1;
	}else{
		queue->data[queue->rear] = dat;
		queue->rear = (queue->rear+1)%(queue->capacity);
	}

	return 0;
}

int out_loop_queue(loop_queue_t *queue, float *dat)
{
	if(empty_loop_queue(queue)){
		return 1;
	}else{
		*dat = queue->data[queue->front];
		 queue->front = (queue->front+1)%(queue->capacity);
	}

	return 0;
}


int get_loop_queue_average(loop_queue_t * queue,float * avg)
{
	int index = queue->front;
	float sum = 0;

	for(int i = 0; i < (queue->capacity-1); i++){
		sum += queue->data[index];
		if(index == queue->rear){
			break;
		}
		index = (index+1)%queue->capacity;
	}

	*avg = sum/(queue->capacity-1);

	return 0;
}

/**
 * Gets the rate of change of elements in the queue.
 */
int get_queue_rate(loop_queue_t * queue,float coef, float * rate)
{
	float first = queue->data[queue->front];
	float last = queue->data[queue->rear];

	*rate = coef*(last - first);

	return 0;
}

int show_loop_queue(loop_queue_t * queue)
{
	int index = queue->front;

	for(int i = 0; i < queue->capacity-1; i++){
		printf("%0.2f ", queue->data[index]);
		if(index == queue->rear){
			break;
		}
		index = (index+1)%queue->capacity;
	}
	putchar(10);
	return 0;
}

int loop_queue_size(loop_queue_t * queue)
{
	return (queue->rear - queue->front + queue->capacity)%(queue->capacity);
}

1.3 main函数调用测试

#include<stdio.h>
#include "loop_queue.h"

int main()
{
    loop_queue_t queue;
    float avg;
    float data;

    init_loop_queue(&queue, 10);

    for(int i = 0; i < 20; i++){
        enter_loop_queue(&queue, i);
    }
    show_loop_queue(&queue);
    
    get_loop_queue_average(&queue, &avg);
    printf("avg:%0.3f \n", avg);

    for(int i = 10; i < 20; i++){
        out_loop_queue(&queue, &data);
        enter_loop_queue(&queue, i);
        show_loop_queue(&queue);
        get_loop_queue_average(&queue, &avg);
        printf("avg:%0.3f \n", avg);
    }
   

    return 0;
}