#!/usr/bin/ruby
#
## https://rosettacode.org/wiki/Taxicab_numbers
#
var (start=1, end=25) = ARGV.map{.to_i}...
func display (h, start, end) {
    var i = start
    for n in [h.grep {|_,v| v.len > 1 }.keys.sort_by{.to_i}[start-1 .. end-1]] {
        printf("%4d %10d  =>\t%s\n", i++, n,
            h{n}.map{ "%4d³ + %-s" % (.first, "#{.last}³") }.join(",\t"))
    }
}
var taxi = Hash()
var taxis = 0
var terminate = 0
for c1 (1..Inf) {
    if (0<terminate && terminate<c1) {
        display(taxi, start, end)
        break
    }
    var c = c1**3
    for c2 (1..c1) {
        var this = (c2**3 + c)
        taxi{this} := [] << [c2, c1]
        ++taxis if (taxi{this}.len == 2)
        if (taxis==end && !terminate) {
            terminate = taxi.grep{|_,v| v.len > 1 }.keys.map{.to_i}.max.root(3)
        }
    }
}