結果

問題 No.1501 酔歩
ユーザー maguroflymagurofly
提出日時 2021-05-07 22:15:28
言語 Ruby
(3.3.0)
結果
WA  
実行時間 -
コード長 4,807 bytes
コンパイル時間 887 ms
コンパイル使用メモリ 7,680 KB
実行使用メモリ 419,812 KB
最終ジャッジ日時 2024-09-15 10:17:58
合計ジャッジ時間 5,176 ms
ジャッジサーバーID
(参考情報)
judge3 / judge5
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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 89 ms
17,664 KB
testcase_01 AC 90 ms
12,288 KB
testcase_02 WA -
testcase_03 WA -
testcase_04 RE -
testcase_05 TLE -
testcase_06 -- -
testcase_07 -- -
testcase_08 -- -
testcase_09 -- -
testcase_10 -- -
testcase_11 -- -
testcase_12 -- -
testcase_13 -- -
testcase_14 -- -
testcase_15 -- -
testcase_16 -- -
testcase_17 -- -
testcase_18 -- -
testcase_19 -- -
testcase_20 -- -
testcase_21 -- -
testcase_22 -- -
testcase_23 -- -
testcase_24 -- -
testcase_25 -- -
testcase_26 -- -
testcase_27 -- -
testcase_28 -- -
testcase_29 -- -
testcase_30 -- -
testcase_31 -- -
testcase_32 -- -
testcase_33 -- -
testcase_34 -- -
testcase_35 -- -
testcase_36 -- -
testcase_37 -- -
testcase_38 -- -
testcase_39 -- -
testcase_40 -- -
testcase_41 -- -
testcase_42 -- -
testcase_43 -- -
testcase_44 -- -
testcase_45 -- -
testcase_46 -- -
testcase_47 -- -
testcase_48 -- -
testcase_49 -- -
testcase_50 -- -
testcase_51 -- -
testcase_52 -- -
testcase_53 -- -
testcase_54 -- -
testcase_55 -- -
権限があれば一括ダウンロードができます
コンパイルメッセージ
Syntax OK

ソースコード

diff #

def main
  @N, @K = ints
  @A = ints.map(&:to_r)
  
  # p[i] = x[i] * p[i + 1]
  # の形で表したい

  # p[0] = x[0] * p[1]; x[0] = A[0] / (A[0] + A[2])
  # p[i] = x[i] * p[i + 1]; x[i] = (1 - A[i] / (A[i - 2] + A[i]) * x[i - 1]) * A[i] / (A[i] + A[i + 2])
  # x[0] = A[0] / (A[0] + A[2])
  x = []
  x[0] = @A[0] / (@A[0] + @A[2])
  x[1] = @A[1] / (@A[1] + @A[3]) if @N > 3
  x[@N - 1] = [@A[@N - 1] / (@A[@N - 1] + @A[@N - 3])]
  (1 .. @N - 3).each do |i|
    x[i] = (1 - @A[i] / (@A[i - 2] + @A[i]) * x[i - 1]) * @A[i] / (@A[i] + @A[i + 2])
  end
  x[@N - 2] = @A[@N - 2] / (@A[@N - 2] + @A[@N - 4]) if @N > 4

  y = 1 - (0 ... @K - 1).inject(1r) { |y, i| y * x[i] }
  
  if y == 0
    puts 0
  else
    puts "#{y.numerator}/#{y.denominator}"
  end
end

DEBUG = true
MOD = 10**9+7
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
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