結果
問題 | No.1124 Earthquake Safety |
ユーザー | maspy |
提出日時 | 2020-07-22 22:49:02 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 935 ms / 3,000 ms |
コード長 | 1,349 bytes |
コンパイル時間 | 933 ms |
コンパイル使用メモリ | 86,832 KB |
実行使用メモリ | 189,256 KB |
最終ジャッジ日時 | 2023-09-05 03:02:23 |
合計ジャッジ時間 | 37,370 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 | 71 ms
71,196 KB |
testcase_01 | AC | 73 ms
71,160 KB |
testcase_02 | AC | 71 ms
71,332 KB |
testcase_03 | AC | 72 ms
71,352 KB |
testcase_04 | AC | 72 ms
71,316 KB |
testcase_05 | AC | 74 ms
70,884 KB |
testcase_06 | AC | 99 ms
75,532 KB |
testcase_07 | AC | 141 ms
79,236 KB |
testcase_08 | AC | 309 ms
107,724 KB |
testcase_09 | AC | 853 ms
175,996 KB |
testcase_10 | AC | 526 ms
174,840 KB |
testcase_11 | AC | 73 ms
71,240 KB |
testcase_12 | AC | 72 ms
71,156 KB |
testcase_13 | AC | 74 ms
71,136 KB |
testcase_14 | AC | 898 ms
176,636 KB |
testcase_15 | AC | 935 ms
176,168 KB |
testcase_16 | AC | 921 ms
175,848 KB |
testcase_17 | AC | 910 ms
176,240 KB |
testcase_18 | AC | 867 ms
176,232 KB |
testcase_19 | AC | 886 ms
176,320 KB |
testcase_20 | AC | 872 ms
176,268 KB |
testcase_21 | AC | 896 ms
176,308 KB |
testcase_22 | AC | 845 ms
175,904 KB |
testcase_23 | AC | 844 ms
175,208 KB |
testcase_24 | AC | 882 ms
175,680 KB |
testcase_25 | AC | 825 ms
176,116 KB |
testcase_26 | AC | 840 ms
175,120 KB |
testcase_27 | AC | 833 ms
175,080 KB |
testcase_28 | AC | 823 ms
176,632 KB |
testcase_29 | AC | 826 ms
176,596 KB |
testcase_30 | AC | 852 ms
176,464 KB |
testcase_31 | AC | 867 ms
176,252 KB |
testcase_32 | AC | 877 ms
176,056 KB |
testcase_33 | AC | 885 ms
175,228 KB |
testcase_34 | AC | 892 ms
174,956 KB |
testcase_35 | AC | 766 ms
184,076 KB |
testcase_36 | AC | 882 ms
174,924 KB |
testcase_37 | AC | 732 ms
183,688 KB |
testcase_38 | AC | 831 ms
178,648 KB |
testcase_39 | AC | 728 ms
177,880 KB |
testcase_40 | AC | 687 ms
181,064 KB |
testcase_41 | AC | 699 ms
178,836 KB |
testcase_42 | AC | 631 ms
188,092 KB |
testcase_43 | AC | 666 ms
182,084 KB |
testcase_44 | AC | 693 ms
177,960 KB |
testcase_45 | AC | 714 ms
183,432 KB |
testcase_46 | AC | 645 ms
176,840 KB |
testcase_47 | AC | 663 ms
178,124 KB |
testcase_48 | AC | 647 ms
187,268 KB |
testcase_49 | AC | 503 ms
189,256 KB |
testcase_50 | AC | 75 ms
71,272 KB |
testcase_51 | AC | 72 ms
71,256 KB |
testcase_52 | AC | 71 ms
71,212 KB |
testcase_53 | AC | 71 ms
71,368 KB |
testcase_54 | AC | 72 ms
71,060 KB |
testcase_55 | AC | 72 ms
71,088 KB |
testcase_56 | AC | 74 ms
71,112 KB |
testcase_57 | AC | 72 ms
71,136 KB |
ソースコード
import sys read = sys.stdin.buffer.read readline = sys.stdin.buffer.readline readlines = sys.stdin.buffer.readlines MOD = 10**9 + 7 inv2 = pow(2, MOD - 2, MOD) inv4 = inv2**2 % MOD def dfs_order(G, root=1): parent = [0] * (N + 1) order = [] stack = [root] while stack: x = stack.pop() order.append(x) for y in G[x]: if y == parent[x]: continue parent[y] = x stack.append(y) return parent, order N = int(readline()) m = map(int, read().split()) G = [[] for _ in range(N + 1)] for a, b in zip(m, m): G[a].append(b) G[b].append(a) root = 1 parent, order = dfs_order(G, root) mu1 = [0] * (N + 1) var1 = [0] * (N + 1) for v in order[::-1]: p = parent[v] mu1[v] += 1 mu1[v] %= MOD var1[v] %= MOD mu1[p] += inv2 * mu1[v] var1[p] += var1[v] * inv2 + mu1[v] * mu1[v] * inv4 mu2 = [0] * (N + 1) var2 = [0] * (N + 1) for v in order: mu2[v] = mu1[v] var2[v] = var1[v] if v == root: continue p = parent[v] mu = mu2[p] - mu1[v] * inv2 var = var2[p] - inv2 * var2[v] - mu1[v]**2 * inv4 mu2[v] += mu * inv2 var2[v] += mu * mu * inv4 + var * inv2 mu2[v] %= MOD var2[v] %= MOD ans = 0 for v in range(1, N+1): ans += mu2[v] ** 2 + var2[v] ans *= pow(2, N-1, MOD) print(ans % MOD)