money_exchanger.tcl

#!/usr/bin/env tclsh

set amount [lindex $::argv 0]
set coins_values [lrange $::argv 1 end]

proc max_coin { coin_list } {
    lindex [lsort -integer $coin_list] end
} 

proc xchange { val biggest } {
    global change
    global coins_values

    set num_of_big [ expr $val / $biggest ]
    for {set x 0} {$x < $num_of_big} {incr x} { lappend change $biggest }
    set rest [ expr $val % $biggest ]
    
    set coins_values [lreplace $coins_values end end]

    if { $rest != 0 } {
        xchange $rest [max_coin $coins_values]
    } else {
        puts $change
    }
}

set change {}
xchange $amount [max_coin $coins_values]