Comment by nish__
2 hours ago
Doesn't every language support multidimensional arrays? It's just an array of arrays, no? What am I missing?
2 hours ago
Doesn't every language support multidimensional arrays? It's just an array of arrays, no? What am I missing?
An array of arrays is an extremely inefficient and error-prone way to represent multidimensional arrays.
If I want a 1000x1000 array, representing it physically as a single 1000000-element array requires one allocation, and processing it element-by-element (assuming it's stored in the same order we're iterating over it) is sequential in memory and therefore very efficient.
Representing it as 1000 separate 1000-element arrays requires 1000 allocations, and pointer-chasing every time we move from one row to the next.
I see. That makes sense.