dynamically allocating atwo dimensional array where each row contains variable number of elements & freeing it in c++

How can I dy开发者_JAVA技巧namically allocate a two dimensional array where each row contains variable element? How can I free this memory?

Actually you probably want a vector of vectors, something like this:

std::vector<std::vector<int> > vector_2d;

This way you'll benefit from the automatic memory management of the vector rather than having to manually manage the memory of an array of pointers to arrays of data.

You would need need to use pointers:

int ** a;
a = new (int*)[5];
for(int i = 0; i<5; i++)
{
    a[i] = new int[x]; //where x is the size of this row
}

Something like this should work, but I didn't test it.

Just for the sake of completeness:

int ** a;
a = new (int*)[5];

for(int i = 0; i<5; i++)
{
    a[i] = new int[x]; //where x is the size of this row
}

for(int i = 0; i<5; i++)
{
    delete[] a[i];
}

detete[] a;