I have python code that contains the following code.
d = {}
d[(0,0)] = 0
d[(1,2)] = 1
d[(2,1)] = 2
d[(2,3)] = 3
d[(3,2)] = 4
for (i,j) in d:
print d[(i,j)], d[(j,i)]
Unfortunately looping over all the keys in python isn't really fast enough for my purpose, and I would like to translate this code to C++. What is the best C++ data structure to use for a python dictionary that has tuples as its keys? What would be the C++ equivalent of the above code?
I looked at sparse matrices in the boost library, but couldn't find an easy way to loop only over the non-zero elements.