What
A randomized algorithm is an algorithm that employs a degree of randomness as part of its logic or procedure. The algorithm typically uses uniformly random bits as an auxiliary input to guide its behavior, in the hope of achieving good performance in the “average case” over all possible choices of random determined by the random bits; thus either the running time, or the output (or both) are random variables.
Generating
Las Vegas Algorithm
Las Vegas algorithm - Wikipedia
It always gives correct results; that is, it always produces the correct result or it informs about the failure.