結果
問題 | No.827 総神童数 |
ユーザー | yuruhiya |
提出日時 | 2020-10-21 21:57:09 |
言語 | Crystal (1.11.2) |
結果 |
AC
|
実行時間 | 187 ms / 2,000 ms |
コード長 | 2,727 bytes |
コンパイル時間 | 20,187 ms |
コンパイル使用メモリ | 255,544 KB |
実行使用メモリ | 46,792 KB |
最終ジャッジ日時 | 2023-09-13 12:24:50 |
合計ジャッジ時間 | 25,625 ms |
ジャッジサーバーID (参考情報) |
judge13 / judge15 |
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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 | 19 ms
14,712 KB |
testcase_01 | AC | 19 ms
15,008 KB |
testcase_02 | AC | 20 ms
15,468 KB |
testcase_03 | AC | 21 ms
14,280 KB |
testcase_04 | AC | 18 ms
15,304 KB |
testcase_05 | AC | 20 ms
15,960 KB |
testcase_06 | AC | 18 ms
14,820 KB |
testcase_07 | AC | 19 ms
15,472 KB |
testcase_08 | AC | 18 ms
14,688 KB |
testcase_09 | AC | 182 ms
46,792 KB |
testcase_10 | AC | 66 ms
26,776 KB |
testcase_11 | AC | 21 ms
15,844 KB |
testcase_12 | AC | 38 ms
19,516 KB |
testcase_13 | AC | 141 ms
41,860 KB |
testcase_14 | AC | 23 ms
17,272 KB |
testcase_15 | AC | 60 ms
25,624 KB |
testcase_16 | AC | 145 ms
39,216 KB |
testcase_17 | AC | 168 ms
42,556 KB |
testcase_18 | AC | 76 ms
27,208 KB |
testcase_19 | AC | 187 ms
35,792 KB |
testcase_20 | AC | 132 ms
31,496 KB |
testcase_21 | AC | 94 ms
27,544 KB |
testcase_22 | AC | 146 ms
32,624 KB |
testcase_23 | AC | 20 ms
14,576 KB |
testcase_24 | AC | 164 ms
33,688 KB |
testcase_25 | AC | 125 ms
31,904 KB |
testcase_26 | AC | 166 ms
34,360 KB |
testcase_27 | AC | 106 ms
28,684 KB |
testcase_28 | AC | 105 ms
27,872 KB |
testcase_29 | AC | 85 ms
25,316 KB |
testcase_30 | AC | 37 ms
17,888 KB |
testcase_31 | AC | 68 ms
22,560 KB |
testcase_32 | AC | 66 ms
22,392 KB |
testcase_33 | AC | 183 ms
35,936 KB |
testcase_34 | AC | 162 ms
34,584 KB |
testcase_35 | AC | 72 ms
22,300 KB |
testcase_36 | AC | 99 ms
27,404 KB |
testcase_37 | AC | 122 ms
29,060 KB |
testcase_38 | AC | 179 ms
34,728 KB |
ソースコード
lib C fun strtoll(s : UInt8*, p : UInt8**, b : Int32) : Int64 end class String def to_i64 C.strtoll(self, nil, 10) end end struct ModInt @@MOD = 1_000_000_007i64 def self.mod @@MOD end def self.zero ModInt.new(0) end def initialize(n) @n = n.to_i64 % @@MOD end getter n : Int64 def + : self self end def - : self ModInt.new(n != 0 ? @@MOD - @n : 0) end def +(m) ModInt.new(@n + m.to_i64 % @@MOD) end def -(m) ModInt.new(@n - m.to_i64 % @@MOD) end def *(m) ModInt.new(@n * m.to_i64 % @@MOD) end def /(m) raise DivisionByZeroError.new if m == 0 a, b, u, v = m.to_i64, @@MOD, 1i64, 0i64 while b != 0 t = a // b a -= t * b a, b = b, a u -= t * v u, v = v, u end ModInt.new(@n * u) end def //(m) self / m end def **(m : Int) t, res = self, ModInt.new(1) while m > 0 res *= t if m.odd? t *= t m >>= 1 end res end def ==(m) @n == m.to_i64 end def !=(m) @n != m.to_i64 end def succ self + 1 end def pred self - 1 end def to_i64 : Int64 @n end delegate to_s, to: @n delegate inspect, to: @n end struct Int def to_mint : ModInt ModInt.new(self) end end class Comb(T) def initialize(@Max = 400009) @fac = Array(T).new(@Max, T.zero) @finv = Array(T).new(@Max, T.zero) @inv = Array(T).new(@Max, T.zero) @fac[0] = @fac[1] = T.new(1) @finv[0] = @finv[1] = T.new(1) @inv[1] = T.new(1) (2...@Max).each do |i| @fac[i] = @fac[i - 1] * i @inv[i] = -@inv[T.mod % i] * (T.mod / i) @finv[i] = @finv[i - 1] * @inv[i] end end def permutation(n, r) (n < r || n < 0 || r < 0) ? T.zero : @fac[n] * @finv[n - r] end def combination(n, r) (n < r || n < 0 || r < 0) ? T.zero : @fac[n] * @finv[r] * @finv[n - r] end def homogeneous_product(n, r) (n < 0 || r < 0) ? T.zero : r == T.zero ? T.new(1) : c(n + r - 1, r) end def factorial(n) @fac[n] end end class Solve @n : Int32 @g : Array(Array(Int32)) @parent_size : Array(Int32) def initialize @n = read_line.to_i @g = Array.new(@n) { [] of Int32 } (@n - 1).times do u, v = read_line.split.map(&.to_i.pred) @g[u] << v @g[v] << u end @parent_size = Array.new(@n, 1) end def dfs(v, prev, size) @parent_size[v] = size @g[v].each do |u| if u != prev dfs(u, v, size + 1) end end end def solve dfs(0, -1, 1) comb = Comb(ModInt).new puts @parent_size.sum { |s| comb.combination(@n, s) * comb.factorial(s - 1) * comb.factorial(@n - s) } end end Solve.new.solve