memory deallocation with delete [] for 2d array with one dimension constant

Question

I allocated a 2D array using new like this

  int (*arr)[2] = new int[x][2];

x is calculated at runtime.

How should I deallocate this memory? I tried

delete [] *arr[0];
delete [] *arr[1]; 

However, valgrind says that their were 13 allocs and 14 frees.

Answer 1

You use one new[] , so you should use one delete[] :

delete[] arr;

The delete[] form applies to any new[] ; there aren't separate cases for new T[x] as for new T[x][2] or anything. An expression like new T[x][2] is actually a single array new where the array element has type "array of 2 T's".