結果
問題 | No.1333 Squared Sum |
ユーザー | toyuzuko |
提出日時 | 2021-04-17 23:27:41 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 1,512 ms / 2,000 ms |
コード長 | 2,688 bytes |
コンパイル時間 | 842 ms |
コンパイル使用メモリ | 86,516 KB |
実行使用メモリ | 214,976 KB |
最終ジャッジ日時 | 2023-09-17 07:22:03 |
合計ジャッジ時間 | 42,429 ms |
ジャッジサーバーID (参考情報) |
judge13 / judge14 |
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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 | 72 ms
70,856 KB |
testcase_01 | AC | 72 ms
70,864 KB |
testcase_02 | AC | 74 ms
70,928 KB |
testcase_03 | AC | 1,440 ms
198,296 KB |
testcase_04 | AC | 1,388 ms
199,088 KB |
testcase_05 | AC | 1,434 ms
199,296 KB |
testcase_06 | AC | 1,512 ms
199,572 KB |
testcase_07 | AC | 1,426 ms
200,016 KB |
testcase_08 | AC | 1,469 ms
198,996 KB |
testcase_09 | AC | 1,461 ms
198,408 KB |
testcase_10 | AC | 1,426 ms
199,764 KB |
testcase_11 | AC | 1,452 ms
198,476 KB |
testcase_12 | AC | 1,462 ms
198,896 KB |
testcase_13 | AC | 893 ms
182,664 KB |
testcase_14 | AC | 1,314 ms
183,820 KB |
testcase_15 | AC | 1,304 ms
184,212 KB |
testcase_16 | AC | 72 ms
70,808 KB |
testcase_17 | AC | 75 ms
70,988 KB |
testcase_18 | AC | 75 ms
70,840 KB |
testcase_19 | AC | 74 ms
71,048 KB |
testcase_20 | AC | 74 ms
70,844 KB |
testcase_21 | AC | 73 ms
70,820 KB |
testcase_22 | AC | 73 ms
71,016 KB |
testcase_23 | AC | 73 ms
70,972 KB |
testcase_24 | AC | 73 ms
70,720 KB |
testcase_25 | AC | 74 ms
70,836 KB |
testcase_26 | AC | 1,443 ms
188,612 KB |
testcase_27 | AC | 1,430 ms
190,444 KB |
testcase_28 | AC | 1,418 ms
189,712 KB |
testcase_29 | AC | 972 ms
186,380 KB |
testcase_30 | AC | 657 ms
126,492 KB |
testcase_31 | AC | 450 ms
104,312 KB |
testcase_32 | AC | 894 ms
145,996 KB |
testcase_33 | AC | 767 ms
132,188 KB |
testcase_34 | AC | 1,210 ms
173,376 KB |
testcase_35 | AC | 915 ms
146,340 KB |
testcase_36 | AC | 628 ms
122,308 KB |
testcase_37 | AC | 614 ms
120,908 KB |
testcase_38 | AC | 688 ms
126,460 KB |
testcase_39 | AC | 1,030 ms
160,856 KB |
testcase_40 | AC | 1,071 ms
214,976 KB |
testcase_41 | AC | 1,043 ms
204,584 KB |
testcase_42 | AC | 1,064 ms
214,452 KB |
testcase_43 | AC | 980 ms
208,888 KB |
ソースコード
class Tree(): def __init__(self, n): self.n = n self.tree = [[] for _ in range(n)] self.cost = dict() self.root = None def add_edge(self, u, v, c): if u > v: u, v = v, u self.tree[u].append(v) self.tree[v].append(u) self.cost[u * self.n + v] = c def get_cost(self, u, v): if u < v: return self.cost[u * self.n + v] else: return self.cost[v * self.n + u] def set_root(self, r=0): self.root = r self.par = [None] * self.n self.ord = [r] stack = [r] while stack: v = stack.pop() for adj in self.tree[v]: if self.par[v] == adj: continue self.par[adj] = v self.ord.append(adj) stack.append(adj) def rerooting(self, op, e, merge, id): if self.root is None: self.set_root() dp = [e] * self.n lt = [id] * self.n rt = [id] * self.n inv = [id] * self.n for v in self.ord[::-1]: tl = tr = e for adj in self.tree[v]: if self.par[v] == adj: continue lt[adj] = tl self.w = self.get_cost(v, adj) tl = op(tl, dp[adj]) for adj in self.tree[v][::-1]: if self.par[v] == adj: continue rt[adj] = tr self.w = self.get_cost(v, adj) tr = op(tr, dp[adj]) dp[v] = tr for v in self.ord: if v == self.root: continue p = self.par[v] if p != self.root: pp = self.par[p] self.w = self.get_cost(p, pp) inv[v] = op(merge(lt[v], rt[v]), inv[p]) else: inv[v] = merge(lt[v], rt[v]) self.w = self.get_cost(v, p) dp[v] = op(dp[v], inv[v]) return dp import sys input = sys.stdin.buffer.readline MOD = 1000000007 N = int(input()) t = Tree(N) for _ in range(N - 1): u, v, w = map(int, input().split()) u -= 1; v -= 1 t.add_edge(u, v, w) e = (1, 0, 0) def op(p, c): ps, pd, pds = p cs, cd, cds = c size = ps + cs w = t.w dist = (pd + cd + w * cs) % MOD dsq = (pds + cds + w**2 * cs + 2 * w * cd) % MOD return size, dist, dsq id = (0, 0, 0) def merge(lt, rt): ls, ld, lds = lt rs, rd, rds = rt size = ls + rs - 1 dist = (ld + rd) % MOD dsq = (lds + rds) % MOD return size, dist, dsq dp = t.rerooting(op, e, merge, id) res = 0 for i in range(N): res += dp[i][2] res %= MOD print(res * pow(2, MOD - 2, MOD) % MOD)