# require "/Scanner" require "io/error" class Scanner def self.s peek = STDIN.peek if not_space = peek.index { |x| x != 32 && x != 10 } if index = peek.index(not_space) { |x| x == 32 || x == 10 } result = String.new(peek[not_space...index]) STDIN.skip(index + 1) result else result = String.new(peek) STDIN.skip(peek.size) result end else raise IO::EOFError.new end end def self.i s.to_i end end macro input_array(type, args) Array.new({{args.first}}) do {% if args.size == 1 %} input({{type.id}}) {% else %} input_array({{type}}, {{args[1...args.size]}}) {% end %} end end macro input(type) {% if type.is_a?(Path) %} {{type}}.new(Scanner.s) {% elsif type.is_a?(Var) %} {% if Scanner.methods.includes?(type.id) %} Scanner.{{type.id}} {% else %} Scanner.s.to_{{type.id}} {% end %} {% elsif type.is_a?(Call) && type.args.size == 0 %} {% if Scanner.methods.includes?(type) %} Scanner.{{type.id}} {% else %} Scanner.s.to_{{type.id}} {% end %} {% elsif type.name == "[]" %} input_array("{{type.receiver}}", {{type.args}}) {% else %} input_array("{{type.name}}", {{type.args}}) {% end %} end macro input(*types) { {% for type in types %} input({{type}}), {% end %} } end # require "/graph" struct Edge(T) include Comparable(Edge(T)) property to : Int32 property cost : T def initialize(@to : Int32, @cost : T) end def <=>(other : Edge(T)) {cost, to} <=> {other.cost, other.to} end def to_s(io) : Nil io << '(' << to << ", " << cost << ')' end def inspect(io) : Nil io << "->#{to}(#{cost})" end end struct Edge2(T) include Comparable(Edge2(T)) property from : Int32 property to : Int32 property cost : T def initialize(@from : Int32, @to : Int32, @cost : T) end def <=>(other : Edge2(T)) {cost, from, to} <=> {other.cost, other.from, other.to} end def reverse Edge2(T).new(to, from, cost) end def to_s(io) : Nil io << '(' << from << ", " << to << ", " << cost << ')' end def inspect(io) : Nil io << "#{from}->#{to}(#{cost})" end end struct UnweightedEdge2 property from : Int32 property to : Int32 def initialize(@from, @to) end def reverse UnweightedEdge2.new(to, from) end def to_s(io) : Nil io << '(' << from << ", " << to << ')' end def inspect(io) : Nil io << "#{from}->#{to}" end end abstract class Graph(T) getter graph : Array(Array(Edge(T))) def initialize(size : Int) raise ArgumentError.new("Negative graph size: #{size}") unless size >= 0 @graph = Array.new(size) { Array(Edge(T)).new } end def add_edge(i : Int32, j : Int32, cost : T) add_edge(Edge2.new(i, j, cost)) end def add_edges(edges : Array(Edge2(T))) edges.each { |edge| add_edge(edge) } self end delegate size, to: @graph delegate :[], to: @graph def each_edge : Nil (0...size).each do |v| graph[v].each do |edge| yield Edge2(T).new(v, edge.to, edge.cost) end end end def edges result = [] of Edge2(T) each_edge do |edge| result << edge end result end end class DirectedGraph(T) < Graph(T) def initialize(size : Int) super end def initialize(size : Int, edges : Array(Edge2(T))) super(size) add_edges(edges) end def add_edge(edge : Edge2(T)) raise IndexError.new unless 0 <= edge.from < size raise IndexError.new unless 0 <= edge.to < size @graph[edge.from] << Edge.new(edge.to, edge.cost) self end end class UndirectedGraph(T) < Graph(T) def initialize(size : Int) super end def initialize(size : Int, edges : Array(Edge2(T))) super(size) add_edges(edges) end def add_edge(edge : Edge2(T)) raise IndexError.new unless 0 <= edge.from < size raise IndexError.new unless 0 <= edge.to < size @graph[edge.from] << Edge.new(edge.to, edge.cost) @graph[edge.to] << Edge.new(edge.from, edge.cost) self end end abstract class UnweightedGraph getter graph : Array(Array(Int32)) def initialize(size : Int) raise ArgumentError.new("Negative graph size: #{size}") unless size >= 0 @graph = Array.new(size) { Array(Int32).new } end def add_edge(i : Int32, j : Int32) add_edge(UnweightedEdge2.new(i, j)) end def add_edges(edges : Array(UnweightedEdge2)) edges.each { |edge| add_edge(edge) } self end delegate size, to: @graph delegate :[], to: @graph def each_edge : Nil (0...size).each do |v| graph[v].each do |u| yield UnweightedEdge2.new(v, u) end end end def edges result = [] of UnweightedEdge2 each_edge do |edge| result << edge end result end end class UnweightedDirectedGraph < UnweightedGraph def initialize(size : Int) super end def initialize(size : Int, edges : Array(UnweightedEdge2)) super(size) add_edges(edges) end def add_edge(edge : UnweightedEdge2) raise IndexError.new unless 0 <= edge.from < size raise IndexError.new unless 0 <= edge.to < size @graph[edge.from] << edge.to self end end class UnweightedUndirectedGraph < UnweightedGraph def initialize(size : Int) super end def initialize(size : Int, edges : Array(UnweightedEdge2)) super(size) add_edges(edges) end def add_edge(edge : UnweightedEdge2) raise IndexError.new unless 0 <= edge.from < size raise IndexError.new unless 0 <= edge.to < size @graph[edge.from] << edge.to @graph[edge.to] << edge.from self end def each_child(vertex : Int, parent, &block) : Nil graph[vertex].each do |u| yield u if u != parent end end def each_child(vertex : Int, parent) graph[vertex].each.select { |u| u != parent } end end module Comparable(T) def max(val : T) Math.max(self, val) end def max0 Math.max(self, typeof(self).zero) end def min(val : T) Math.min(self, val) end end class UnweightedUndirectedGraph def solve(v, par) : {Int32, Int32} ab = each_child(v, par).map { |u| solve(u, v) }.to_a b = ab.sum(0, &.[0]) a = b + (ab.max_of? { |x, y| y - x }.try(&.succ) || 0).max0 {a, b} end end n = input(i) puts UnweightedUndirectedGraph.new(n, Array.new(n - 1) { |time| i, j = input(i, i) UnweightedEdge2.new(i - 1, j - 1) }).solve(0, nil).max