二维数组动态分配

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代码转自：http://blog.csdn.net/lifanxi/article/details/1649840

#include <iostream>#include <cstdlib>#include <new>template <typename T>T **darray_new(int row, int col){    int size = sizeof(T);    void **arr = (void **) malloc(sizeof(void *) * row + size * row * col);    if (arr != NULL)    {        unsigned char * head;        head = (unsigned char *) arr + sizeof(void *) * row;        for (int i = 0; i < row; ++i)        {            arr[i] =  head + size * i * col;            for (int j = 0; j < col; ++j)                new (head + size * (i * col + j)) T;        }    }    return (T**) arr;}template <typename T>void darray_free(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);}

代码转自：http://blog.csdn.net/MoreWindows/article/details/7664479

//C++语言中动态的申请二维数组 new delete  #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;  }

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