I'm not sure the final version of Equihash has been settled yet so it may not be possible until after 1.0 parameters have been set. And don't forget the Zcash team has said that they are open to changing the POW later if needed.
is there any chance that the PoW wont be equihash for mainnet genesis?
I am assuming the changes to k and n etc. are all parameters that any solver can adjust to, so it seems a C miner made now will have extremely high probability of working with initial mainnet.
Regardless, the bounty will be paid for a working pure C miner against the current testnet.
I doubt that the POW would change before Genesis unless a major problem is found in testing. Just out of curiosity why would you want pure C rather than C++? Familiarity with C or trying to eek a little more performance out of the compilation?
I am fluent in C, not in C++
plus it is more efficient, or at least can be
Yes, it's very unlikely that the proof of work will change from Equihash before launch. The only reason for that to happen would be if a major problem with Equihash were found that violated our security goals for the proof of work.