栈和队列【数据结构】

1、栈

（1）Stack.h

#pragma once
#include 
#include 
#include 
#include 

typedef int STDataType;

typedef struct Stack
{
	STDataType* a;
	int top;
	int capacity;
}ST;

void STInit(ST* pst);
void STDestroy(ST* pst);
void STPush(ST* pst, STDataType x);
void STPop(ST* pst);
STDataType STTop(ST* pst);
bool STEmpty(ST* pst);
int STSize(ST* pst);

（2）Stack.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Stack.h"

void STInit(ST* pst)
{
	assert(pst);
	pst->a = NULL;
	
	//pst->top = -1; //top指向栈顶数据
	pst->top = 0; //top指向栈顶数据的下一个

	pst->capacity = 0;
}

void STDestroy(ST* pst)
{
	assert(pst);
	free(pst->a);
	pst->a = NULL;
	pst->capacity = 0;
	pst->top = 0;
}

void STPush(ST* pst, STDataType x)
{
	if (pst->top == pst->capacity) //top指向栈顶数据的下一个，下一个元素的下标数就是当前已有元素总数
	{
		int newCapacity = pst->capacity == 0 ? 4 : pst->capacity * 2;
		STDataType* tem = (STDataType*)realloc(pst->a, newCapacity * sizeof(STDataType));
		if (tem == NULL)
		{
			perror("realloc fail");
			return;
		}
		pst->a = tem;
		pst->capacity = newCapacity;
	}
	pst->a[pst->top] = x;
	pst->top++;
}

void STPop(ST* pst)
{
	assert(pst);
	assert(!STEmpty(pst));
	pst->top--;
}

STDataType STTop(ST* pst)
{
	assert(pst);
	assert(!STEmpty(pst));
	return pst->a[pst->top - 1];
}

bool STEmpty(ST* pst)
{
	assert(pst);
	return pst->top == 0;
}

int STSize(ST* pst)
{
	assert(pst);
	return pst->top;
}

（3）Test.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Stack.h"

int main()
{
	ST st;
	STInit(&st);
	STPush(&st, 1);
	STPush(&st, 2);
	printf("%d ", STTop(&st));
	STPop(&st);
	printf("%d ", STTop(&st));
	printf("\n");

	STPush(&st, 2);
	STPush(&st, 3);
	STPush(&st, 4);
	while (!STEmpty(&st))
	{
		printf("%d ", STTop(&st));
		STPop(&st);
	}

	STDestroy(&st);

	return 0;
}

2、队列

（1）Queue.h

#pragma once
#include 
#include 
#include 
#include 

typedef int QDataType;

typedef struct QueueNode
{
	QDataType data;
	struct QueueNode* next;
}QNode;

typedef struct Queue
{
	QNode* phead;
	QNode* ptail;
	int size;
}Queue;

void QueueInit(Queue* pq);
void QueueDestroy(Queue* pq);
void QueuePush(Queue* pq, QDataType x);
void QueuePop(Queue* pq);
QDataType QueueFront(Queue* pq);
QDataType QueueBack(Queue* pq);
int QueueSize(Queue* pq);
bool QueueEmpty(Queue* pq);

（2）Queue.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Queue.h"

void QueueInit(Queue* pq)
{
	assert(pq);
	pq->phead = NULL;
	pq->ptail = NULL;
	pq->size = 0;
}

void QueueDestroy(Queue* pq)
{
	assert(pq);
	QNode* cur = pq->phead;
	while (cur)
	{
		QNode* next = cur->next;
		free(cur);
		cur = next;
	}
	pq->phead = pq->ptail = NULL;
	pq->size = 0;
}

void QueuePush(Queue* pq, QDataType x)
{
	assert(pq);

	QNode* newnode = (QNode*)malloc(sizeof(QNode));
	if (newnode == NULL)
	{
		perror("malloc fail\n");
		return;
	}
	newnode->next = NULL;
	newnode->data = x;

	if (pq->ptail == NULL)
	{
		assert(pq->phead == NULL);
		pq->phead = pq->ptail = newnode;
	}
	else
	{
		pq->ptail->next = newnode;
		pq->ptail = newnode;
	}
	pq->size++;
}

void QueuePop(Queue* pq)
{
	assert(pq);
	assert(!QueueEmpty(pq));

	//1、一个节点
	//2、多个节点
	if (pq->phead->next == NULL)
	{
		free(pq->phead);
		pq->phead = pq->ptail = NULL;
	}
	else
	{
		//头删
		QNode* next = pq->phead->next;
		free(pq->phead);
		pq->phead = next;
	}
	pq->size--;
}

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;
}

bool QueueEmpty(Queue* pq)
{
	assert(pq);

	//return pq->phead == NULL && pq->ptail == NULL;
	return pq->size == 0;
}

（3）Test.c

#define _CRT_SECURE_NO_WARNINGS 1
#include "Queue.h"

int main()
{
	Queue q;

	QueueInit(&q);

	QueuePush(&q, 1);
	QueuePush(&q, 2);
	QueuePush(&q, 3);
	QueuePush(&q, 4);
	QueuePush(&q, 5);

	printf("Size：%d\n", QueueSize(&q));

	while (!QueueEmpty(&q))
	{
		printf("%d ", QueueFront(&q));
		QueuePop(&q);
	}
	printf("\n");

	QueueDestroy(&q);
	return 0;
}