数据结构和算法--队列的数组实现

柔情只为你懂 2022-07-15 08:00 140阅读 0赞

//循环队列(队列的顺序存储)的实现
    //注意：如果想实现循环队列，那么队列里面最多能够存放N-1个数据
    
    #include <stdio.h>
    #include <stdlib.h>
    
    #define N 32
    
    //定义数据类型
    typedef int datatype_t;
    
    //定义结构体
    typedef struct{
    	datatype_t data[N];
    	int front; //第一项的角标  
    	int rear; //最后一项的角标 默认没有赋值状
    }sequeue_t;
    
    //创建一个空的队列
    sequeue_t *sequeue_create()
    {
    	sequeue_t *sq = (sequeue_t *)malloc(sizeof(sequeue_t));
    
    	sq->front = sq->rear = 0;
    
    	return sq;
    }
    
    //判断队列是否为满
    int sequeue_full(sequeue_t *sq)
    {
    	return sq->front == (sq->rear + 1) % N ? 1 : 0;
    }
    
    //判断队列是否为空
    int sequeue_empty(sequeue_t *sq)
    {
    	return sq->front == sq->rear ? 1 : 0;
    }
    
    //入队
    int sequeue_input(sequeue_t *sq, datatype_t value)
    {
    	if(sequeue_full(sq))
    	{
    		printf("sequeue is full\n");
    		return -1;
    	}
    
    	sq->data[sq->rear] = value;// 赋值 
    	sq->rear = (sq->rear + 1) % N;//给表示最后一项空项的角标赋值 
    
    	return 0;
    }
    
    //出队
    datatype_t sequeue_output(sequeue_t *sq)
    {
    	datatype_t value;
    
    	if(sequeue_empty(sq))
    	{
    		printf("sequeue is empty\n");
    		return (datatype_t)-1;
    	}
    
    	value = sq->data[sq->front];
    	sq->front = (sq->front + 1) % N;//如果有数据则头部指针加一  只是指针加一 数据未动 
    	
    	return value;
    }
    
    int main(int argc, const char *argv[])
    {
    	sequeue_t *sq = sequeue_create();
    
    	sequeue_input(sq, 10);
    	sequeue_input(sq, 20);
    	sequeue_input(sq, 30);
    	sequeue_input(sq, 40);
    	sequeue_input(sq, 50);
    
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    	printf("del = %d\n", sequeue_output(sq));
    
    	return 0;
    }