Question

key is :(x,y) , that means 2 integers.

value is: 0 or 1.

And I have frequently operation of iteration of this hash map.

Which data structure is fit? I am using C++ stl or tr1. Don’t consider boost.

Answer 1

Well, the data format stored obviously is a bool.

And for the key format, if you would know the bitsize of those integers and performance is a must, I would use a associative array (called a map in C++) with twice the bitwidth integers as key:

bool val = true;
uint32 x, y; // key
uint64 combo = x << 32 + y;

std::map<uint64, bool> container;

But this would work fine too and is semantically much better:

std::map<std::pair<int, int>, bool> container.