Linear Congruential Generator Algorithm

A linear congruential generator is an algorithm for producing a sequence of pseudorandom numbers using a simple recurrence: each new value is found by multiplying the previous value by a fixed multiplier, adding a fixed increment, and then taking the remainder after dividing by a fixed modulus. This basic approach makes it one of the oldest and best understood methods of generating pseudorandom numbers, and its simplicity lets it run fast even on early, limited computer hardware. An earlier related method, the Lehmer generator, was published in 1951, and W. E. Thomson and A. Rotenberg published the modern linear congruential form in 1958. The technique's reputation was later damaged by poorly chosen parameter values in specific implementations, most famously the RANDU generator widely used in the early 1970s, whose flawed output pattern is now known to have thrown off the results of many scientific calculations that relied on it.