@VashisthMalik_twitter The contest announcement has a lot of starting links, two good resources are https://docs.microsoft.com/quantum and https://github.com/Microsoft/QuantumKatas/, the latter have a lot of practice problems with solutions worked out. Enjoy the contest!
@githg22_gitlab: Taking a hint from the problem statement itself, I'd suggest that the last sentence is especially relevant here.
"This operation can be implemented using just the X gate and its controlled variants."
And I can't find a way to test it locally through python
I've got a small question, Can we apply the unwrapping operator on LittleEndian? I don't think we can do that because of the no-clone theorem, I can solve the increment problem with array of qubits, but cannot wrap my mind to do that on LittleEndian. I couldn't find any relevant operation in Microsoft.Quantum.Arithematic to apply X gate on Little Endian either...
Just write
!
Just write
register!
Stupid gitter
LittleEndian is basically a different name for Qubit[], literally no other difference
I mean, I get what you mean, but I still find it a bit uncomfortable without having to use
using()
Also, as a side question, does the changes that we make on the unwrapped array reflected automatically in the user-defined LittleEndian?
So umm
Cam you give a hint as to how you solved the problem?
I've been stuck at this for the past 24 hours
I hope it isn't against the protocol, say you've got N=3. On a paper, write down the values in LittleEndian format from 0 to 7 and then write down the required result, again in LittleEndian format. You'll notice something, one of the qubits will always flip no matter what while the others will flip if a certain condition is satisfied(hence the usage of Controlled X) I hope this will help you.
Also, I tried using the unwrap operator and I got a compilation error saying the expression can only be applied on user-defined type while LittleEndian is a custom user-defined(Microsoft.Quantum.Arithematic.LittleEndian)
Its not against the rules btw, in warmup you're free to discuss hints
like the expression?
For example
Yeah I solved C
Any hints?
C is actually similar to a problem in Quantum Katas
It's kind of a hack-y method
nevermind, I'm stupid.
wasted 24 hours on something this stupid
Were you writing LittleEndian instead of register?
@githg22_gitlab: If you allocate an extra qubit, then it has to be returned to |0⟩ at the end of the
using block. As you note, you can't use measurement to do that in an adjointable operation; given that resetting is a special case of measurement, the Reset operation will also fail to preserve adjointability. The trick is that you need to coherently reset the qubit to |0⟩ without measurement. You can do that because you know exactly what state it's in at the end of the using, and can unprepare it using only unitary operations. The within/apply feature of Q# or the ApplyWithCA operation will be very handy here.
By the way, @crazy4pi314 will be streaming with @bettinaheim about the Q# compiler today in a little under three hours if anyone is interested to join at https://twitch.tv/crazy4pi314. More details at https://twitter.com/crazy4pi314/status/1271837229221101569.