[CongruenceModulo] Functions I made for solving problems in the Khan Academy excercises on Congruence Modulo. Usefull stuff to understand when learning about cryptograpy, like the RSA algorithm used in SSL/TSL as used in HTTPS. If two values A and B gives the same result when doing mod(A, C) and mod(B, C) then they are in the same equivalence cl…

CongruenceModulo.jl

# check if A is congruent to B modulo C.
in_same_equivalence_class(A, B, C) = mod(A, C) == mod(B, C)

# find all X in Xs where X is congruent to B modulo C
function find_numbers_in_same_equivalence_class(A, C, Xs)
  r = mod(A, C)
  filter(X->mod(X,C) == r, Xs)
end