数据结构与算法-第五章双向队列-优快云博客

本文详细介绍了一种高效的数据结构——双端队列(Deque)的C语言实现。包括初始化、销毁、判断空满状态、获取容量和大小、头部尾部插入删除元素等操作，并通过一个简单的测试案例展示了其使用方法。

Dequeuer.h

#ifndef _DEQUE_H__
#define _DEQUE_H__

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>

typedef int T;

typedef struct Deque{
	T *m_vect;    //存储元素的内存空间
	size_t cap;   //总容量
	size_t size;  //当前元素的个数
	size_t index; //队首的位置
	
}Deque;

void init(Deque *deq,size_t cap);
void destroy(Deque *deq);
bool isEmpty(Deque *deq);
bool isFull(Deque *deq);
size_t getCap(Deque *deq);
size_t getSize(Deque *deq);
void pushHead(Deque *deq,T data);
void pushTail(Deque *deq,T data);
T popHead(Deque *deq);
T popTail(Deque *deq);
T peekHead(Deque *deq);
T peekTail(Deque *deq);
void travel(Deque *deq);
void clear(Deque *deq);

#endif //_DEQUE_H__

Dequeuer.c

#include "deque.h"
/*
typedef int T;

typedef struct Deque{
	T *m_vect;    //存储元素的内存空间
	size_t cap;   //总容量
	size_t size;  //当前元素的个数
	size_t index; //队首的位置
	
}Deque;
*/
void init(Deque *deq,size_t cap){
	deq->m_vect = calloc(cap,sizeof(T));	
	deq->cap = cap;
	deq->size = 0;
	deq->index = 0;
}
void destroy(Deque *deq){
	if(deq->m_vect != NULL){
		free(deq->m_vect);
		deq->m_vect = NULL;
	}	
}
bool isEmpty(Deque *deq){
	return deq->size == 0;	
}
bool isFull(Deque *deq){
	return deq->cap == deq->size;	
}
size_t getCap(Deque *deq){
	return deq->cap;	
}
size_t getSize(Deque *deq){
	return deq->size;	
}
void pushHead(Deque *deq,T data){
	/*
	if(deq->index==0){
		deq->index = deq->cap-1;	
	}else{
		--deq->index;	
	}*/
	deq->index = deq->index==0?deq->cap-1:deq->index-1;
	deq->m_vect[deq->index] = data;
	++deq->size;
}
void pushTail(Deque *deq,T data){
	deq->m_vect[(deq->size+deq->index)%deq->cap] = data;
	++deq->size;
}
T popHead(Deque *deq){
	T data = deq->m_vect[deq->index];
	deq->index = (deq->index+1)%deq->cap;
	--deq->size;
	return data;
}
T popTail(Deque *deq){
	T data = deq->m_vect[(deq->size+deq->index-1)%deq->cap];	
	--deq->size;
	return data;//return deq->m_vect[(--deq->size+deq->index)%deq->cap];
}
T peekHead(Deque *deq){
	return deq->m_vect[deq->index];	
}
T peekTail(Deque *deq){
	return deq->m_vect[(deq->index+deq->size-1)%deq->cap];	
}
void travel(Deque *deq){
	for(int i=0;i<deq->size;i++){
		printf("%d ",deq->m_vect[(deq->index+i)%deq->cap]);	
	}	
	printf("\n");
}
void clear(Deque *deq){
	while(!isEmpty(deq)){
		popTail(deq);
	}	
	//deq->size = 0;
	//deq->index = 0;
}

Test.c

#include "deque.h"


int main(){
	Deque deq;
	init(&deq,6);
	pushHead(&deq,10);
	pushTail(&deq,20);
	pushHead(&deq,30);
	pushTail(&deq,40);
	pushHead(&deq,50);
	pushTail(&deq,60);
	//50 30 10 20 40 60
	while(!isEmpty(&deq)){
		//printf("%d ",popHead(&deq));	
		printf("%d ",popTail(&deq));	
	}
	printf("\n");

	destroy(&deq);
	
	return 0;	
}