数据结构之队列

    不多说了，功力深厚的筒子就无情地鄙视我吧。基本的数据结构，很多地方可能会用到。比如按层遍历二叉树，就需要用到队列的东西。反倒是那写比较高深的数据结构不太常用，比如伸展树，我在工作中真没碰到。这两天无法静心学习其他的东西，就写写数据结构的代码吧。

queue.h   

#ifndef __QUEUE_H__
#define __QUEUE_H__

typedef struct Queue_node
{
    void *data;
    struct Queue_node* next;
}Queue_node;

typedef struct Queue
{
    struct Queue_node * head;
    struct Queue_node *tail;
}Queue;


int queue_init(struct Queue* self);
int queue_empty(struct Queue* self);
int queue_put(struct Queue* self, void* data);
void* queue_get(struct Queue* self);

#endif

queue.c

#include "queue.h"
#include <stdlib.h>
#include <assert.h>
int queue_init(struct Queue* self)
{
    if(self == NULL)
        return -1;
    else
    {
        self->head = NULL;
        self->tail = NULL;
    }
    return 0;
}

int queue_empty(struct Queue* self)
{
    return self->head == NULL;
}

int queue_put(struct Queue* self, void* data)
{
    assert(self != NULL && data != NULL);
    struct Queue_node *newnode = (struct Queue_node*)malloc(sizeof(Queue_node));
    if(newnode == NULL)
        return -1;
    else
    {
        newnode->data = data;
        newnode->next = NULL;
        if(self->head == NULL)
        {
            self->head = newnode;
            self->tail = newnode;
        }
        else
        {
            self->tail->next = newnode;
            self->tail = newnode;
        }
        return 0;
    }

}

void* queue_get(struct Queue* self)
{
    void* data = NULL;
    if(queue_empty(self) == 1)
        return NULL;
    else
    {
        data = self->head->data;
        struct Queue_node* next = self->head->next;
        free(self->head);
        self->head=next;
        return data;
    }
}

queue_test.c

#include "queue.h"
#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int test_queue()
{
    struct Queue queue;
    int ret = queue_init(&queue);
    if(ret < 0)
    {
        fprintf(stderr,"queue init failed\n");
        return -1;
    }
    int data_array[10] = {0};
    int i = 0;
    srand(time(NULL));
    while(i<10)
    {
        data_array[i] = rand()%100;
        fprintf(stdout,"%d\t",data_array[i]);
        ret = queue_put(&queue,&data_array[i]);
        if(ret < 0)
        {
            fprintf(stderr,"put failed\n");
            return -2;
        }
        i++;
    }
    fprintf(stdout,"\n");

    int *p;
    while(queue_empty(&queue)==0)
    {
        p =(int*) queue_get(&queue);
        fprintf(stdout,"%d\t" ,*p);
    }
    fprintf(stdout,"\n");
    return 0;
}

int main()
{
    test_queue();
    return 0;
}

输出：

root@manu:~/code/c/self/queue# ./test
81	88	66	10	69	97	67	6	37	7
81	88	66	10	69	97	67	6	37	7

参考文献：
1 算法：C语言实现