#657200 (Ruby) No.1507 Road Blocked

提出ソース

結果

問題	No.1507 Road Blocked
ユーザー	magurofly
提出日時	2021-05-14 22:51:38
言語	Ruby (3.3.0)
結果	RE
実行時間	-
コード長	5,133 bytes
コンパイル時間	47 ms
コンパイル使用メモリ	7,808 KB
実行使用メモリ	33,920 KB
最終ジャッジ日時	2024-10-02 03:16:59
合計ジャッジ時間	15,000 ms
ジャッジサーバーID （参考情報）	judge3 / judge1

このコードへのチャレンジ
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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	76 ms 12,032 KB
testcase_01	AC	78 ms 12,160 KB
testcase_02	AC	80 ms 12,288 KB
testcase_03	RE	-
testcase_04	AC	443 ms 32,896 KB
testcase_05	AC	449 ms 33,024 KB
testcase_06	AC	454 ms 32,768 KB
testcase_07	AC	447 ms 32,768 KB
testcase_08	AC	447 ms 32,768 KB
testcase_09	AC	469 ms 32,896 KB
testcase_10	AC	459 ms 32,768 KB
testcase_11	AC	448 ms 33,024 KB
testcase_12	AC	448 ms 32,896 KB
testcase_13	AC	446 ms 33,024 KB
testcase_14	AC	442 ms 33,024 KB
testcase_15	AC	453 ms 32,896 KB
testcase_16	AC	448 ms 32,768 KB
testcase_17	AC	446 ms 33,024 KB
testcase_18	AC	440 ms 32,896 KB
testcase_19	AC	449 ms 32,768 KB
testcase_20	AC	442 ms 32,896 KB
testcase_21	AC	442 ms 32,640 KB
testcase_22	AC	444 ms 33,024 KB
testcase_23	AC	440 ms 33,024 KB
testcase_24	AC	439 ms 32,896 KB
testcase_25	AC	450 ms 32,896 KB
testcase_26	AC	450 ms 32,896 KB
testcase_27	AC	444 ms 33,024 KB
testcase_28	AC	442 ms 32,896 KB
testcase_29	AC	445 ms 32,896 KB
testcase_30	AC	442 ms 32,896 KB
testcase_31	AC	446 ms 32,896 KB
testcase_32	AC	444 ms 33,024 KB

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コンパイルメッセージ

Syntax OK

ソースコード

raw source code

def main
  @N = int
  f = Factorial.new(@N)
  e = []
  g = Array.new(@N) { [] }
  (@N - 1).times do
    u, v = int1s
    e << [u, v]
    g[u] << v
    g[v] << u
  end

  size = Array.new(@N, nil)
  dfs = ->(u) {
    size[u] = 1
    g[u].each do |v|
      next if size[v]
      dfs[v]
      size[u] += size[v]
    end
  }
  dfs[0]

  debug size

  n_inv = f.comb(@N, 2).mod_inv

  ans = 0
  e.each do |(u, v)|
    a = min(size[u], size[v])
    b = @N - a
    debug [a, b, f.comb(a, 2) + f.comb(b, 2)]
    ans += (f.comb(a, 2) + f.comb(b, 2)) * n_inv
    ans %= MOD
  end

  ans *= (@N - 1).mod_inv
  ans %= MOD

  puts ans
end

class Factorial
  def initialize(limit, mod = MOD)
    @mod = mod
    @fac = [1, 1]
    @fin = [1, 1]
    @inv = [nil, 1]
    (2 .. limit).each do |i|
      @inv[i] = mod - @inv[mod % i] * (mod / i) % mod
      @fac[i] = @fac[i - 1] * i % mod
      @fin[i] = @fin[i - 1] * @inv[i] % mod
    end
  end
  
  def fact(n)
    @fac[n]
  end
  
  def comb(n, k)
    return 0 if n < k or n < 0 or k < 0
    @fac[n] * @fin[k] % @mod * @fin[n - k] % @mod
  end
end

DEBUG = false
MOD = 998244353
YESNO = %w(No Yes)
INF = 10**9

def int; gets.to_s.to_i end
def ints; gets.to_s.split.map { |s| s.to_i } end
def int1s; gets.to_s.split.map { |s| s.to_i - 1 } end
def intss(n); Array.new(n) { ints }; end
def float; gets.to_s.to_f end
def floats; gets.to_s.split.map { |s| s.to_f } end
def array_of(&convert); gets.to_s.split.map(&convert) end
def string; gets.to_s.chomp end
def rep(n, &b); Array.new(n, &b) end
def yes; puts YESNO[1] end
def no; puts YESNO[0] end
def yesno t; puts YESNO[t] end
def zip(xs, *yss); Enumerator.new { |y| xs.zip(*yss) { |a| y.yield(*a) } } end
def max(*xs, &block); block_given? ? xs.max_by(&block) : xs.max end
def min(*xs, &block); block_given? ? xs.min_by(&block) : xs.min end
def minmax(*xs, &block); block_given? ? xs.minmax_by(&block) : xs.minmax end
def gcd(*xs); xs.inject(0, :gcd) end
def matrix(h, w, fill=nil, &block); return Array.new(h) { Array.new(w, &block) } if block_given?; Array.new(h) { [fill] * w } end
def debug(x = nil); STDERR.puts (block_given? ? yield(x) : x).inspect if DEBUG; x end
def debug_grid(grid, width = 1); grid.each { |row| STDERR.puts row.map { |x| x.inspect.ljust(width) }.join("") } if DEBUG; grid end
def if_debug; yield if DEBUG end

module Boolean
  def coerce(other); [other, to_i] end
  def +@; to_i end
  def to_int; to_i end
  def *(other); to_i * other end
end

class TrueClass
  include Boolean
  def to_i; 1 end
end

class FalseClass
  include Boolean
  def to_i; 0 end
end

class Integer
  def div_ceil(y); (self + y - 1) / y end
  def mod_inv(mod = MOD); pow(mod-2, mod) end
  def mod_div(y, mod = MOD); self * mod_inv(y, mod) % mod end
  def factorial(mod = MOD); (2..self).inject(1) { |f, x| f * x % mod } end
  def popcount; x = self; c = 0; while x > 0; c += 1 if x & 1 == 1; x >>= 1 end; c end #TODO: faster
  def bitbrute(&block); (1<<self).times(&block) end
  def nCr(r); x = 1; (1..r).each { |i| x *= self + 1 - i; x /= i }; x; end
  def each_divisor; return Enumerator.new { |y| each_divisor { |k| y << k } } unless block_given?; k = 1; while k * k < self; if self % k == 0; yield k; yield self / k end; k += 1; end; yield k if k * k == self end
  def divisors; each_divisor.to_a end
end

class Range
  def end_open; exclude_end? ? self.end : self.end + 1 end
  def end_close; exclude_end? ? self.end - 1 : self.end end
  def upper_bound; ac, wa = self.begin, self.end_open; while wa - ac > 1; if yield((wj = (ac + wa) / 2)); ac = wj else wa = wj end; end; yield(ac) ? ac : nil end
  def lower_bound; ac, wa = self.end_open, self.begin; while ac - wa > 1; if yield((wj = (ac + wa) / 2)); ac = wj else wa = wj end; end; yield(ac) ? ac : nil end
  def shakutori(r2, &pred); Enumerator.new { |y| j, r = r2.begin, r2.end_open; each { |i| j += 1 while j + 1 < r and pred[i, j+1]; y.yield(i, j) } }; end
  def widest(&block); Enumerator.new { |y| j, n = self.begin, self.end_open; each { |i| j += 1 while j < n and block[i, j]; y.yield(i, j) if block[i, j] } } end
  def pairs; Enumerator.new { |y| l, r = self.begin, self.end_open; i = l; while i < r - 1; j = i + 1; while j < r; y.yield(i, j); j += 1 end; i += 1 end } end
end

class Array
  def power(&block); (0 ... 1 << size).each(&block) end
  def sorted_merge(other); a = []; i = j = 0; n, m = size, other.size; if j < m and other[j] < self[i]; a << other[j]; j += 1 else; a << self[i]; i += 1 end while i < n; a.push(*other[j..-1]) if j < m; a end
  def upper_bound; ac, wa = 0, size; while wa - ac > 1; if yield(self[(wj = (ac + wa) / 2)]); ac = wj else; wa = wj end; end; ac end
  def lower_bound; ac, wa = size, 0; while wa - ac > 1; if yield(self[(wj = (ac + wa) / 2)]); ac = wj else; wa = wj end; end; ac end
  def cum(*xs, &op); a = []; a << xs[0] if xs.size > 0; a << x = self[0]; (1...size).each { |i| a << x = op[x, self[i]] }; a end
  def cumdiff(range); self[range.end_open] - self[range.begin]; end
end

module Enumerable
  def sorted_uniq; x = nil; filter { |y| c = x === y; x = y; !c } end
  def cumsum; ys = [0]; each { |x| ys << x + ys[-1] }; ys end
end

main

yukicoder

結果

テストケース

コンパイルメッセージ

ソースコード