IMPORTANT: Please do not post solutions, hints, or other spoilers until at least 60 hours after the date of this message. Thanks. IMPORTANTE: Por favor, no enviéis soluciones, pistas, o cualquier otra cosa que pueda echar a perder la resolución del problema hasta que hayan pasado por lo menos 60 horas desde el envío de este mensaje. Gracias. IMPORTANT: S'il vous plaît, attendez au minimum 60 heures après la date de ce message avant de poster solutions, indices ou autres révélations. Merci. WICHTIG: Bitte schicken Sie keine Lösungen, Tipps oder Hinweise für diese Aufgabe vor Ablauf von 60 Stunden nach dem Datum dieser Mail. Danke. Qing3 Zhu4Yi4: Qing3 Ning2 Deng3Dao4 Jie1Dao4 Ben3 Xin4Xi2 Zhi1Hou4 60 Xiao3Shi2, Zai4 Fa1Biao3 Jie3Da2, Ti2Shi4, Huo4 Qi2Ta1 Hui4 Xie4Lou4 Da2An4 De5 Jian4Yi4. Xie4Xie4. ---------------------------------------------------------------- You will write a function that lays out tree diagrams. layout_tree's arguments will be (1) an object that represents a tree, and (2) an optional hash containing some configuration parameters. The tree object is opaque to your function, but is guaranteed to support at least the following methods: \$tree->children Returns a list of tree objects that represent the subtrees of this tree \$tree->text Returns a reference to an array of strings that show how the root node of this tree should be displayed. An example \$tree object might be manufactured by the following class: package ExampleTree; # Create a new tree object # arguments: ->(label of root node, # [arguments for child 1], # [arguments for child 2], # ...); sub new { my (\$pack, \$label, @subnodes) = @_; my @subobjects = map \$pack->new(@\$_), @subnodes; bless [\$label, @subobjects] => \$pack; } # If the label of the tree node is 'foo', # we format it like this: # +-----+ # | foo | # +-----+ sub text { my \$self = shift; my \$label = \$self->[0]; my \$ln = length \$label; \$label .= " " x (5 - \$ln) if \$ln < 5; # pad with spaces to width 5 \$ln = length \$label; my \$top = "+" . "-" x \$ln . "+"; return [\$top, "|\$label|", \$top]; } sub children { my \$self = shift; my @children = @\$self; shift @children; # throw away the label @children; } And then one might create such an object by calling my \$t = ExampleTree->new("5", ["4 1", ["3 1 1", ["2 1 1 1", ["1 1 1 1 1"], ], ], ["2 2 1"] ], ["3 2"]); layout_tree(\$t) would then manufacture an array of strings, which, when printed, would look something like this: +-----+ |5 | +-----+ ,-' `--------. +-----+ +-----+ |4 1 | |3 2 | +-----+ +-----+ ,-' `----. +-----+ +-----+ |3 1 1| |2 2 1| +-----+ +-----+ | +-------+ |2 1 1 1| +-------+ | +---------+ |1 1 1 1 1| +---------+ Details of exactly how this is laid out and what it looks like are up to you; you might produce output like this instead: +-----+ +-----+ +-----+ +-------+ +---------+ |5 |-+-|4 1 |-+-|3 1 1|---|2 1 1 1|---|1 1 1 1 1| +-----+ | +-----+ | +-----+ +-------+ +---------+ | | | | +-----+ | +-|2 2 1| | +-----+ | +-----+ +-|3 2 | +-----+ However, the tree node displays returned by ->text must appear in the output exactly as they were returned, and it must be possible to understand the tree structure from looking at the output.