project-euler/Sidef/007 10001st prime -- v3.sf

#!/usr/bin/ruby

# Author: Trizen
# Date: 15 March 2023
# https://github.com/trizen

# https://projecteuler.net/problem=7

# Runtime: 0.236s

var n = 10_001
var upper = int(n*(n.log + n.log.log))

var p = upper.bsearch_le {|p|
    p.prime_count <=> n
}

say p.inc.prev_prime