33,321
社区成员




//列大小固定的二维数组可以申请一维数据并将指针强转成二维数组
//By MoreWindows-(http://blog.csdn.net/MoreWindows)
#include <stdio.h>
int main()
{
printf(" 列大小固定的二维数组可以申请一维数据并将指针强转成二维数组\n");
printf(" -- by MoreWindows( http://blog.csdn.net/MoreWindows ) --\n\n");
//列值固定
const int MAXCOL = 3;
int nRow;
printf("请输入二维数组的行数(列值固定为%d): ", MAXCOL);
scanf("%d", &nRow);
//申请一维数据并将其转成二维数组指针
int *pp_arr = new int[nRow * MAXCOL];
int (*p)[MAXCOL] = (int(*)[MAXCOL])pp_arr;
//为二维数组赋值
int i, j;
for (i = 0; i < nRow; i++)
for (j = 0; j < MAXCOL; j++)
p[i][j] = i + j;
//输出二维数组
for (i = 0; i < nRow; i++)
{
for (j = 0; j < MAXCOL; j++)
printf("%5d", p[i][j]);
putchar('\n');
}
//释放资源
delete[] pp_arr;
return 0;
}
//C语言中动态的申请二维数组 malloc free
//By MoreWindows-(http://blog.csdn.net/MoreWindows)
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
//动态申请二维数组
template <typename T>
T** malloc_Array2D(int row, int col)
{
int size = sizeof(T);
int point_size = sizeof(T*);
//先申请内存,其中point_size * row表示存放row个行指针
T **arr = (T **) malloc(point_size * row + size * row * col);
if (arr != NULL)
{
memset(arr, 0, point_size * row + size * row * col);
T *head = (T*)((int)arr + point_size * row);
while (row--)
arr[row] = (T*)((int)head + row * col * size);
}
return (T**)arr;
}
//释放二维数组
void free_Aarray2D(void **arr)
{
if (arr != NULL)
free(arr);
}
int main()
{
printf(" C语言中动态的申请二维数组 malloc free\n");
printf(" -- by MoreWindows( http://blog.csdn.net/MoreWindows ) --\n\n");
printf("请输入行列(以空格分开): ");
int nRow, nCol;
scanf("%d %d", &nRow, &nCol);
//动态申请连续的二维数组
int **p = malloc_Array2D<int>(nRow, nCol);
//为二维数组赋值
int i, j;
for (i = 0; i < nRow; i++)
for (j = 0; j < nCol; j++)
p[i][j] = i + j;
//输出二维数组
for (i = 0; i < nRow; i++)
{
for (j = 0; j < nCol; j++)
printf("%4d ", p[i][j]);
putchar('\n');
}
free_Aarray2D((void**)p);
return 0;
}
//C++语言中动态的申请二维数组 new delete
//By MoreWindows-(http://blog.csdn.net/MoreWindows)
#include <new>
#include <cstdio>
#include <cstdlib>
#include <string>
using namespace std;
//动态申请二维数组
template <typename T>
T** new_Array2D(int row, int col)
{
int size = sizeof(T);
int point_size = sizeof(T*);
//先申请内存,其中sizeof(T*) * row表示存放row个行指针
T **arr = (T **) malloc(point_size * row + size * row * col);
if (arr != NULL)
{
T *head = (T*)((int)arr + point_size * row);
for (int i = 0; i < row; ++i)
{
arr[i] = (T*)((int)head + i * col * size);
for (int j = 0; j < col; ++j)
new (&arr[i][j]) T;
}
}
return (T**)arr;
}
//释放二维数组
template <typename T>
void delete_Array2D(T **arr, int row, int col)
{
for (int i = 0; i < row; ++i)
for (int j = 0; j < col; ++j)
arr[i][j].~T();
if (arr != NULL)
free((void**)arr);
}
int main()
{
printf(" C++语言中动态的申请二维数组 new delete\n");
printf(" -- by MoreWindows( http://blog.csdn.net/MoreWindows ) --\n\n");
printf("请输入行列(以空格分开): ");
int nRow, nCol;
scanf("%d %d", &nRow, &nCol);
//动态申请连续的二维数组
string **p = new_Array2D<string>(nRow, nCol);
//为二维数组赋值
int i, j;
for (i = 0; i < nRow; i++)
for (j = 0; j < nCol; j++)
{
char szTemp[30];
sprintf(szTemp, "(第%d行,第%d列)", i, j);
p[i][j] = szTemp;
}
//输出二维数组
for (i = 0; i < nRow; i++)
{
for (j = 0; j < nCol; j++)
printf("%s ", p[i][j].c_str());
putchar('\n');
}
delete_Array2D<string>(p, nRow, nCol);
return 0;
}