In C++, which is the way to access a 2D array sequentially (memory block wise)

Edit: I've removed the faster/more efficient from the question title as it was misleading..my intention was not optimisation but understanding arrays. Sorry for the trouble!

int array[10][10], i, j;

for(i=0;i<10;i++)
{
    for(j=0;j<10;j++)
        std::cin>>array[i][j];
}

Versus

int array[10][10], i, j;

for(i=0;i<10;i++)
{
    for(j=0;j<10;j++)
        std::cin>>array[j][i];
}

I'm pretty sure the answer has to do with how arrays are implemented on a hardware level; that the [ ][ ] syntax is just a programmer's abstraction to aid visualisation/modelling. However, I forgot which of the above code accesses the memory block sequentially from start till end...

Thanks for all the answers...

Just to confirm my understanding, does this mean the first code is equivalent to

int array[10][10], k;

for(k=0;k<100;k++)
{
    std::cin>>*(array+k);
}