Q# Quantum Computer
To understand the behaviour displayed by this program: imagine taking a coin and starting with heads up, then flipping it. It has a 50% chance of coming up heads or tails. You check what it is, then flip it again. It has a 50% chance of coming up heads or tails again. Pretty straight forward. Now, here is the quantum weirdness. In the quantum realm, if the coin is a particle subject to quantum effects, you flip it by sending it through an quantum logic circuit called a Hadamard gate. If you look at it after the first flip, you get a 50/50 heads/tails on that flip and on the second flip. However, if you don’t look at it after the first flip, the second flip comes up heads — every single time.