26 lines
849 B
Text
26 lines
849 B
Text
using Printf
|
|
|
|
function sternbrocot(f::Function=(x) -> length(x) ≥ 20)::Vector{Int}
|
|
rst = Int[1, 1]
|
|
i = 3
|
|
while !f(rst)
|
|
append!(rst, Int[rst[i-1] + rst[i-2], rst[i-2]])
|
|
i += 1
|
|
end
|
|
return rst
|
|
end
|
|
|
|
println("First 15 elements of Stern-Brocot series:\n", sternbrocot(x -> length(x) ≥ 15)[1:15], "\n")
|
|
|
|
for i in (1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 100)
|
|
occurr = findfirst(x -> x == i, sternbrocot(x -> i ∈ x))
|
|
@printf("Index of first occurrence of %3i in the series: %4i\n", i, occurr)
|
|
end
|
|
|
|
print("\nAssertion: the greatest common divisor of all the two\nconsecutive members of the series up to the 1000th member, is always one: ")
|
|
sb = sternbrocot(x -> length(x) > 1000)
|
|
if all(gcd(prev, this) == 1 for (prev, this) in zip(sb[1:1000], sb[2:1000]))
|
|
println("Confirmed.")
|
|
else
|
|
println("Rejected.")
|
|
end
|