数据结构之循环队列（C语言）_数据结构循环队列代码

一、循环队列的定义

循环队列是把顺序队列首尾相连，把存储队列元素的表从逻辑上看成一个环，成为循环队列。循环队列就是将队列存储空间的最后一个位置绕到第一个位置，形成逻辑上的环状空间，供队列循环使用。

二、代码功能

1、创建循环队列

2、循环队列的初始化

3、循环队列元素的入队

4、循环队列元素的出队

5、循环队列的输出

6、循环队列的测试

7、程序入口

8、运行结果

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三、循环队列的代码

1、创建循环队列

typedef struct CircleIntQueue
{
	int data[TOTAL_SPACE];
 
	int head;
 
	int tail;
}*CircleIntQueuePtr;

2、循环队列的初始化

CircleIntQueuePtr initQueue()
{
	CircleIntQueuePtr resultPtr = (CircleIntQueuePtr)malloc(sizeof(struct CircleIntQueue));
	resultPtr->head = 0;
	resultPtr->tail = 0;
 
	return resultPtr;
}

3、循环队列元素的入队

void enqueue(CircleIntQueuePtr paraPtr, int paraValue)
{
	if ((paraPtr->tail + 1) % TOTAL_SPACE == paraPtr->head) {
		printf("Queue full.\r\n");
		return;
	} // Of if
 
	paraPtr->data[paraPtr->tail % TOTAL_SPACE] = paraValue;
	paraPtr->tail++;
}

4、循环队列元素的出队

int dequeue(CircleIntQueuePtr paraPtr)
{
	int resultValue;
	if (paraPtr->head == paraPtr->tail) {
		printf("No element in the queue.\r\n");
		return -1;
	} // Of if
 
	resultValue = paraPtr->data[paraPtr->head % TOTAL_SPACE];
	paraPtr->head++;
 
	return resultValue;
}

5、循环队列的输出

void outputLinkQueue(CircleIntQueuePtr paraPtr)
{
	int i;
	if (paraPtr->head == paraPtr->tail)
	{
		printf("Empty queue.");
		return;
	} // Of if
 
	printf("Elements in the queue: ");
	for (i = paraPtr->head; i < paraPtr->tail; i++)
	{
		printf("%d, ", paraPtr->data[i % TOTAL_SPACE]);
	} // Of for i
 
	printf("\r\n");
}

6、循环队列的测试

void testLinkQueue()
{
	int i = 10;
	CircleIntQueuePtr tempPtr = initQueue();
	for (; i < 16; i ++)
	{
		enqueue(tempPtr, i);
	}//Of for i
 
	outputLinkQueue(tempPtr);
 
	for (i = 0; i < 6; i ++)
	{
		printf("dequeue gets %d\r\n", dequeue(tempPtr));
	}//Of for i
 
	enqueue(tempPtr, 8);
	outputLinkQueue(tempPtr);
}

7、程序入口

int main()
{
	testLinkQueue();
	return 1;
}

8、运行结果

Queue full.
Queue full.
Elements in the queue: 10, 11, 12, 13,
dequeue gets 10
dequeue gets 11
dequeue gets 12
dequeue gets 13
No element in the queue.
dequeue gets -1
No element in the queue.
dequeue gets -1
Elements in the queue: 8,

四、整体代码

#include <stdio.h>
#include <malloc.h>
 
#define TOTAL_SPACE 5
 
/**
 * Circle int queue.
 */
typedef struct CircleIntQueue
{
	int data[TOTAL_SPACE];
 
	int head;
 
	int tail;
}*CircleIntQueuePtr;
 
/**
 * Initialize the queue.
 */
CircleIntQueuePtr initQueue()
{
	CircleIntQueuePtr resultPtr = (CircleIntQueuePtr)malloc(sizeof(struct CircleIntQueue));
	resultPtr->head = 0;
	resultPtr->tail = 0;
 
	return resultPtr;
}// Of the first constructor
 
/**
 * Enqueue.
 * 
 * @param paraValue The value of the new node.
 */
void enqueue(CircleIntQueuePtr paraPtr, int paraValue)
{
	if ((paraPtr->tail + 1) % TOTAL_SPACE == paraPtr->head) {
		printf("Queue full.\r\n");
		return;
	} // Of if
 
	paraPtr->data[paraPtr->tail % TOTAL_SPACE] = paraValue;
	paraPtr->tail++;
}// Of enqueue
 
/**
 * Dequeue.
 * 
 * @return The value at the head.
 */
int dequeue(CircleIntQueuePtr paraPtr)
{
	int resultValue;
	if (paraPtr->head == paraPtr->tail) {
		printf("No element in the queue.\r\n");
		return -1;
	} // Of if
 
	resultValue = paraPtr->data[paraPtr->head % TOTAL_SPACE];
	paraPtr->head++;
 
	return resultValue;
}// Of dequeue
 
/**
 * Output the queue.
 */
void outputLinkQueue(CircleIntQueuePtr paraPtr)
{
	int i;
	if (paraPtr->head == paraPtr->tail)
	{
		printf("Empty queue.");
		return;
	} // Of if
 
	printf("Elements in the queue: ");
	for (i = paraPtr->head; i < paraPtr->tail; i++)
	{
		printf("%d, ", paraPtr->data[i % TOTAL_SPACE]);
	} // Of for i
 
	printf("\r\n");
}//Of outputLinkQueue
 
/**
 * Unit test.
 */
void testLinkQueue()
{
	int i = 10;
	CircleIntQueuePtr tempPtr = initQueue();
	for (; i < 16; i ++)
	{
		enqueue(tempPtr, i);
	}//Of for i
 
	outputLinkQueue(tempPtr);
 
	for (i = 0; i < 6; i ++)
	{
		printf("dequeue gets %d\r\n", dequeue(tempPtr));
	}//Of for i
 
	enqueue(tempPtr, 8);
	outputLinkQueue(tempPtr);
}//Of testLinkQueue
 
/**
 * The entrance.
 */
int main()
{
	testLinkQueue();
	return 1;
}