二级指针的三种内存模型

Posted 2020-09-17 牠说，要陪你走过春夏秋冬；牠必不食言

第一种内存模型：

/*
 Module:		二级指针第一种内存模型.cpp
 Notices:		Copyright (c) 2017 Landy Tan
*/


#include <iostream>
using namespace std;


/////////////////////////////////////////////////


#define SIZE(a) sizeof(a) / sizeof(a[0])
int SortArray(char **pArray, int nLen);
int OutputArray(char **pArray, int nLen);


/////////////////////////////////////////////////


int main()
{
	char* pArray[] = { "333", "111", "444", "222", "666" };
	cout << "Before sorting..." << endl;
	OutputArray(pArray, SIZE(pArray));

	SortArray(pArray, SIZE(pArray));

	cout << "After sorting..." << endl;
	OutputArray(pArray, SIZE(pArray));

	system("pause");
	return 0;
}


/////////////////////////////////////////////////


int SortArray(char **pArray, int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
	{
		for (int j = i; j < nLen; j++)
		{
			if (strcmp(*(pArray + i), *(pArray + j)) > 0)
			{	// Modify the pointer to the point.
				char *pTmp = *(pArray + i);
				*(pArray + i) = *(pArray + j);
				*(pArray + j) = pTmp;
			}
		}
	}
	return 0;
}


/////////////////////////////////////////////////


int OutputArray(char **pArray, int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
		cout << *(pArray + i) << endl;
	return 0;
}


//////////////// End of File ////////////////////

　　

 

第二种内存模型：

/*
 Module:		二级指针第二种内存模型.cpp
 Notices:		Copyright (c) 2017 Landy Tan
*/


#include <iostream>
using namespace std;


/////////////////////////////////////////////////


#define SIZE(a) sizeof(a) / sizeof(a[0])
int SortArray(char(*pArray)[30], int nLen);
int OutputArray(char(*pArray)[30], int nLen);


/////////////////////////////////////////////////


int main()
{
	char pArray[][30] = { "333", "111", "444", "222", "666" };
	cout << "Before sorting..." << endl;
	OutputArray(pArray, SIZE(pArray));

	SortArray(pArray, SIZE(pArray));

	cout << "After sorting..." << endl;
	OutputArray(pArray, SIZE(pArray));

	system("pause");
	return 0;
}


/////////////////////////////////////////////////


int SortArray(char(*pArray)[30], int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
	{
		for (int j = i; j < nLen; j++)
		{
			if (strcmp(*(pArray + i), *(pArray + j)) > 0)
			{	// Modify the data pointed to by the pointer.
				char sz[30] = { 0 };
				strcpy_s(sz, *(pArray + i));
				strcpy_s(*(pArray + i), *(pArray + j));
				strcpy_s(*(pArray + j), sz);
			}
		}
	}
	return 0;
}


/////////////////////////////////////////////////


int OutputArray(char(*pArray)[30], int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
		cout << *(pArray + i) << endl;
	return 0;
}


//////////////// End of File ////////////////////

　　

 

 

第三种内存模型：

/*
Module:			二级指针第三种内存模型.cpp
Notices:		Copyright (c) 2017 Landy Tan
*/


#include <iostream>
using namespace std;


/////////////////////////////////////////////////


int SortArray(char **pArray, int nLen);
int OutputArray(char **pArray, int nLen);
int NewBuffer(char ***pBuf, int nLen1, int nLen2);
void DeleteBuffer(char ***pBuf, int nLen1);

/////////////////////////////////////////////////


int main()
{
	char **pBuf;
	NewBuffer(&pBuf, 5, 30);
	if (pBuf == NULL)
	{
		cout << "New buffer error." << endl;
		system("pause");
		return -1;
	}
	strcpy_s(*(pBuf + 0), 30, "333");
	strcpy_s(*(pBuf + 1), 30, "111");
	strcpy_s(*(pBuf + 2), 30, "444");
	strcpy_s(*(pBuf + 3), 30, "222");
	strcpy_s(*(pBuf + 4), 30, "666");


	cout << "Before sorting..." << endl;
	OutputArray(pBuf, 5);

	SortArray(pBuf, 5);

	cout << "After sorting..." << endl;
	OutputArray(pBuf, 5);

	DeleteBuffer(&pBuf, 5);
	system("pause");
	return 0;
}


/////////////////////////////////////////////////


int SortArray(char **pArray, int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
	{
		for (int j = i; j < nLen; j++)
		{
			if (strcmp(*(pArray + i), *(pArray + j)) > 0)
			{	

			}
		}
	}
	return 0;
}


/////////////////////////////////////////////////


int OutputArray(char **pArray, int nLen)
{
	if (pArray == NULL || nLen <= 0)
		return -1;

	for (int i = 0; i < nLen; i++)
		cout << *(pArray + i) << endl;
	return 0;
}


/////////////////////////////////////////////////


int NewBuffer(char ***pBuf, int nLen1, int nLen2)
{
	if (pBuf == NULL || nLen1 <= 0 || nLen2 <= 0)
		return -1;
	char **p = *pBuf;
	p = new char*[nLen1];
	for (int i = 0; i < nLen1; ++i)
	{
		p[i] = new char[nLen2]{ 0 };
	}
	*pBuf = p;
	return 0;
}


/////////////////////////////////////////////////


void DeleteBuffer(char ***pBuf, int nLen1)
{
	if (pBuf == NULL)
		return ;

	char **p = *pBuf;
	for (int i = 0; i < nLen1; i++)
	{
		delete[] p[i];
		p[i] = NULL;
		
	}
	delete[] p;
	p = NULL;

	*pBuf = p;
	return;
}


//////////////// End of File ////////////////////