say sum_primes(2e6) #=> 142913828922
func sum_primes(limit) {
var sum = 0
for (var p = 2; p < limit; p.next_prime!) {
sum += p
}
return sum
}
say sum_primes(2e6)
func sum_of_primes(n) {
return 0 if (n <= 1)
var r = n.isqrt
var V = (1..r -> map {|k| idiv(n,k) })
V << range(V.last-1, 1, -1).to_a...
var S = Hash(V.map{|k| (k, polygonal(k,3)) }...)
for p in (2..r) {
S{p} > S{p-1} || next
var sp = S{p-1}
var p2 = p*p
V.each {|v|
break if (v < p2)
S{v} -= p*(S{idiv(v,p)} - sp)
}
}
return S{n}-1
}
say sum_of_primes(2e6)