結果
問題 | No.827 総神童数 |
ユーザー | Coki628 |
提出日時 | 2020-08-17 18:00:16 |
言語 | PyPy3 (7.3.13) |
結果 |
AC
|
実行時間 | 561 ms / 2,000 ms |
コード長 | 2,026 bytes |
コンパイル時間 | 1,837 ms |
コンパイル使用メモリ | 87,044 KB |
実行使用メモリ | 106,396 KB |
最終ジャッジ日時 | 2023-08-01 19:59:51 |
合計ジャッジ時間 | 16,724 ms |
ジャッジサーバーID (参考情報) |
judge13 / judge15 |
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 | 73 ms
71,580 KB |
testcase_01 | AC | 79 ms
71,620 KB |
testcase_02 | AC | 76 ms
71,828 KB |
testcase_03 | AC | 77 ms
71,788 KB |
testcase_04 | AC | 74 ms
71,532 KB |
testcase_05 | AC | 77 ms
71,632 KB |
testcase_06 | AC | 76 ms
71,812 KB |
testcase_07 | AC | 78 ms
71,624 KB |
testcase_08 | AC | 78 ms
71,796 KB |
testcase_09 | AC | 475 ms
106,116 KB |
testcase_10 | AC | 219 ms
89,100 KB |
testcase_11 | AC | 105 ms
77,396 KB |
testcase_12 | AC | 155 ms
81,340 KB |
testcase_13 | AC | 381 ms
101,480 KB |
testcase_14 | AC | 114 ms
79,180 KB |
testcase_15 | AC | 214 ms
86,096 KB |
testcase_16 | AC | 358 ms
101,456 KB |
testcase_17 | AC | 442 ms
106,124 KB |
testcase_18 | AC | 236 ms
90,268 KB |
testcase_19 | AC | 561 ms
106,360 KB |
testcase_20 | AC | 422 ms
99,512 KB |
testcase_21 | AC | 335 ms
94,296 KB |
testcase_22 | AC | 454 ms
101,284 KB |
testcase_23 | AC | 102 ms
77,136 KB |
testcase_24 | AC | 490 ms
102,080 KB |
testcase_25 | AC | 392 ms
99,224 KB |
testcase_26 | AC | 495 ms
102,068 KB |
testcase_27 | AC | 357 ms
95,372 KB |
testcase_28 | AC | 345 ms
95,168 KB |
testcase_29 | AC | 299 ms
91,016 KB |
testcase_30 | AC | 159 ms
80,840 KB |
testcase_31 | AC | 251 ms
88,868 KB |
testcase_32 | AC | 242 ms
88,724 KB |
testcase_33 | AC | 543 ms
106,396 KB |
testcase_34 | AC | 485 ms
101,836 KB |
testcase_35 | AC | 259 ms
89,256 KB |
testcase_36 | AC | 331 ms
94,340 KB |
testcase_37 | AC | 415 ms
99,216 KB |
testcase_38 | AC | 533 ms
105,916 KB |
ソースコード
import sys def input(): return sys.stdin.readline().strip() def list2d(a, b, c): return [[c] * b for i in range(a)] def list3d(a, b, c, d): return [[[d] * c for j in range(b)] for i in range(a)] def list4d(a, b, c, d, e): return [[[[e] * d for j in range(c)] for j in range(b)] for i in range(a)] def ceil(x, y=1): return int(-(-x // y)) def INT(): return int(input()) def MAP(): return map(int, input().split()) def LIST(N=None): return list(MAP()) if N is None else [INT() for i in range(N)] def Yes(): print('Yes') def No(): print('No') def YES(): print('YES') def NO(): print('NO') sys.setrecursionlimit(10 ** 9) INF = 10 ** 19 MOD = 10 ** 9 + 7 EPS = 10 ** -10 class ModTools: """ 階乗・逆元用のテーブルを構築する """ def __init__(self, MAX, MOD): # nCrならn、nHrならn+rまで作る MAX += 1 self.MAX = MAX self.MOD = MOD factorial = [1] * MAX factorial[0] = factorial[1] = 1 for i in range(2, MAX): factorial[i] = factorial[i-1] * i % MOD inverse = [1] * MAX inverse[MAX-1] = pow(factorial[MAX-1], MOD-2, MOD) for i in range(MAX-2, -1, -1): inverse[i] = inverse[i+1] * (i+1) % MOD self.fact = factorial self.inv = inverse def div(self, x, y): """ MOD除算 """ return x * pow(y, self.MOD-2, self.MOD) % self.MOD def dfs(nodes, src): """ DFS(木、スタック、重みなし) """ N = len(nodes) stack = [(src, -1)] dist = [INF] * N dist[src] = 0 while stack: u, prev = stack.pop() for v in nodes[u]: if v != prev: dist[v] = dist[u] + 1 stack.append((v, u)) return dist N = INT() mt = ModTools(N, MOD) nodes = [[] for i in range(N)] for _ in range(N-1): a, b = MAP() a -= 1; b -= 1 nodes[a].append(b) nodes[b].append(a) depth = dfs(nodes, 0) ans = 0 for i in range(N): ans += mt.div(mt.fact[N], depth[i]+1) ans %= MOD print(ans)