创建一个类DoubleSubscr iptedArray。在构造阶段，该类能够创建一个包含任意行、任意列的数组。类还提供operator()函数进行双下标运算。例如，在一个名为a的3行5列的二维数组中，可以用a(1，3)访问第一行第三列的元素。函数operator( )应能执行相应的指针运算来访问数组中的元素。。这个类还提供以下运算符：“==”，“!=”，“=”，“<<”，“>>”。-Create a class DoubleSubscr iptedArray. In the construction phase, the class can contain any number of rows to create an array of any column. Class also provides operator () function double subscr ipt operator. For example, in a line called a three-dimensional array of five, can be a (1,3) to access the first row, third column elements. Function operator () should be able to perform the appropriate pointer arithmetic to access array elements. . This class also provides the following operators: "! =" "==", "=", "<<" ">>."