Given a number, produce another random number that is the same every time and distinct from all other results
This sounds like a non-repeating random number generator. There are several possible approaches to this.
As described in this article, we can generate them by selecting a prime number p and satisfies p % 4 = 3 that is large enough (greater than the maximum value in the output range) and generate them this way:
int randomNumberUnique(int range_len , int p , int x)
if(x * 2 < p)
return (x * x) % p
else
return p - (x * x) % p
This algorithm will cover all values in [0 , p) for an input in range [0 , p).