coins_game.tcl

#!/usr/bin/env tclsh

set coins_pile $::argv

proc take_left {} {
    global coins_pile

    set taken [lindex $coins_pile 0]
    set coins_pile [lreplace $coins_pile 0 0]

    return $taken
}

proc take_right {} {
    global coins_pile

    set taken [lindex $coins_pile end]
    set coins_pile [lreplace $coins_pile end end]

    return $taken
}

proc take_best_coin {} {
    global coins_pile

    set left_half  [lrange $coins_pile 0 [expr [llength $coins_pile] / 2 - 1] ]
    set right_half [lrange $coins_pile [expr [llength $coins_pile] / 2] end]

    # puts "LH: $left_half"
    # puts "RH: $right_half"

    set left_sum 0
    foreach coin $left_half { set left_sum [expr $left_sum + $coin] }
    set right_sum 0
    foreach coin $right_half { set right_sum [expr $right_sum + $coin] }

    #    if { [lindex $coins_pile end] > [lindex $coins_pile 0] } {}

    if { $right_sum > $left_sum } {
        return [take_right]
    } else {
        return [take_left]
    }
}

if { [ expr [llength $coins_pile] % 2 ] != 0  } {
    puts "Amount of coins is not even, exiting"
    exit 1
}

set property(me) {}
set property(partner) {}

while { [llength $coins_pile] > 0 } {
    foreach player {me partner} { 
        lappend property($player) [take_best_coin] 
    }
}

puts "My coins are:        $property(me)"
puts "Partners' coins are: $property(partner)"

set sum 0
foreach coin $property(me) { set sum [expr $sum + $coin] }

puts "I won: $sum"