1.队列
1.1 概念与结构
概念:只允许在一端插入数据操作,在另一端进行删除数据操作的特殊线性表,队列具有先进先出FIFO(First In First Out)
入队列:进行插入操作的一端称为队尾
出队列:进行删除操作的一端称为队头
2.源码
2.1 Queue.h
#pragma once#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdbool.h>//定义队列结构typedef int QDataType;typedef struct QueueNode
{int data;struct QueueNode* next;
}QueueNode;typedef struct Queue
{QueueNode* phead;QueueNode* ptail;int size;
}Queue;void QueueInit(Queue* pq);//初始化void QueuePush(Queue* pq, QDataType x);//入队列void QueuePop(Queue* pq);//出队列bool QueueEmpty(Queue* pq);//队列判空QDataType QueueFront(Queue* pq);//取队头数据QDataType QueueBack(Queue* pq);//取队尾数据int QueueSize(Queue* pq);//取有效数据个数void QueueDestroy(Queue* pq);//队列的销毁
2.2 Queue.c
#include "Queue.h"void QueueInit(Queue* pq)
{assert(pq);pq->phead = pq->ptail = NULL;pq->size = 0;
}void QueuePush(Queue* pq, QDataType x)
{assert(pq);//申请新节点QueueNode* newnode = (QueueNode*)malloc(sizeof(QueueNode));if (newnode == NULL){perror("malloc fail!");exit(1);}newnode->data = x;newnode->next = NULL;//ptail newnodeif (pq->phead == NULL)//队列为空{pq->phead = pq->ptail = newnode;}else//队列不为空{//队列不为空pq->ptail->next = newnode;pq->ptail = pq->ptail->next;}pq->size++;
}
//
void QueuePop(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));//只有一个节点的情况(避免出现野指针)if (pq->ptail == pq->phead){free(pq->phead);pq->phead = pq->ptail = NULL;}else{//删除队头元素QueueNode* next = pq->phead->next;free(pq->phead);pq->phead = next;}pq->size--;
}//空位true ,非空为false
bool QueueEmpty(Queue* pq)
{assert(pq);return pq->phead = NULL && pq->ptail == NULL;
}
//
QDataType QueueFront(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));return pq->phead->data;
}
//
QDataType QueueBack(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));return pq->ptail->data;
}int QueueSize(Queue* pq)
{assert(pq);return pq->size;
}void QueueDestroy(Queue* pq)
{assert(pq);assert(!QueueEmpty(pq));QueueNode* pcur = pq->phead;while (pcur){QueueNode* next = pcur->next;free(pcur);pcur = next;}pq->phead = pq->ptail = NULL;
}
2.3 test.c
#include "Queue.h"void QueueTest01()
{Queue q;QueueInit(&q);QueuePush(&q, 1);QueuePush(&q, 2);QueuePush(&q, 3);//QueuePop(&q);printf("head:&d\n", QueueFront(&q));printf("head:&d\n", QueueBack(&q));}int main()
{QueueTest01();return 0;
}