結果
問題 | No.1553 Lovely City |
ユーザー | Kiri8128 |
提出日時 | 2021-06-18 22:50:48 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 991 ms / 2,000 ms |
コード長 | 4,080 bytes |
コンパイル時間 | 316 ms |
コンパイル使用メモリ | 87,200 KB |
実行使用メモリ | 210,708 KB |
最終ジャッジ日時 | 2023-09-04 23:58:11 |
合計ジャッジ時間 | 23,505 ms |
ジャッジサーバーID (参考情報) |
judge15 / judge11 |
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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
70,764 KB |
testcase_01 | AC | 72 ms
71,156 KB |
testcase_02 | AC | 444 ms
167,068 KB |
testcase_03 | AC | 84 ms
70,936 KB |
testcase_04 | AC | 80 ms
71,056 KB |
testcase_05 | AC | 90 ms
76,180 KB |
testcase_06 | AC | 82 ms
75,432 KB |
testcase_07 | AC | 80 ms
75,108 KB |
testcase_08 | AC | 667 ms
157,388 KB |
testcase_09 | AC | 694 ms
163,280 KB |
testcase_10 | AC | 747 ms
173,552 KB |
testcase_11 | AC | 576 ms
147,260 KB |
testcase_12 | AC | 813 ms
182,064 KB |
testcase_13 | AC | 625 ms
146,028 KB |
testcase_14 | AC | 649 ms
159,292 KB |
testcase_15 | AC | 632 ms
158,416 KB |
testcase_16 | AC | 717 ms
168,292 KB |
testcase_17 | AC | 590 ms
153,212 KB |
testcase_18 | AC | 969 ms
207,572 KB |
testcase_19 | AC | 991 ms
209,480 KB |
testcase_20 | AC | 920 ms
208,700 KB |
testcase_21 | AC | 898 ms
210,708 KB |
testcase_22 | AC | 918 ms
207,300 KB |
testcase_23 | AC | 933 ms
207,196 KB |
testcase_24 | AC | 911 ms
207,796 KB |
testcase_25 | AC | 937 ms
207,940 KB |
testcase_26 | AC | 948 ms
210,128 KB |
testcase_27 | AC | 908 ms
207,868 KB |
ソースコード
class UnionFind(): def __init__(self, n): self.n = n self.PA = [-1] * n def root(self, a): L = [] while self.PA[a] >= 0: L.append(a) a = self.PA[a] for l in L: self.PA[l] = a return a def unite(self, a, b): ra, rb = self.root(a), self.root(b) if ra != rb: if self.PA[rb] >= self.PA[ra]: self.PA[ra] += self.PA[rb] self.PA[rb] = ra else: self.PA[rb] += self.PA[ra] self.PA[ra] = rb def size(self, a): return -self.PA[self.root(a)] def groups(self): G = [[] for _ in range(self.n)] for i in range(self.n): G[self.root(i)].append(i) return [g for g in G if g] def groups_index(self): G = [[] for _ in range(self.n)] for i in range(self.n): G[self.root(i)].append(i) cnt = 0 GG = [] I = [-1] * self.n for i in range(self.n): if G[i]: GG.append(G[i]) I[i] = cnt cnt += 1 return GG, I def group_size(self): G = [[] for _ in range(self.n)] for i in range(self.n): G[self.root(i)].append(i) return [len(g) for g in G if g] def scc(E): n = len(E) iE = [[] for _ in range(n)] for i, e in enumerate(E): for v in e: iE[v].append(i) T = [] done = [0] * n # 0 -> 1 -> 2 ct = 0 for i0 in range(n): if done[i0]: continue Q = [~i0, i0] while Q: i = Q.pop() if i < 0: if done[~i] == 2: continue done[~i] = 2 T.append(~i) ct += 1 continue if i >= 0: if done[i]: continue done[i] = 1 for j in E[i]: if done[j]: continue Q.append(~j) Q.append(j) done = [0] * n SCC = [] ### ID が必要なとき I = [0] * n ### for i0 in T[::-1]: if done[i0]: continue L = [] Q = [~i0, i0] while Q: i = Q.pop() if i < 0: if done[~i] == 2: continue done[~i] = 2 L.append(~i) ### I[~i] = len(SCC) ### continue if i >= 0: if done[i]: continue done[i] = 1 for j in iE[i]: if done[j]: continue Q.append(~j) Q.append(j) SCC.append(L) return SCC, I ### ↓ Edge が必要なとき (上の return を消す) nE = [set() for _ in range(len(SCC))] iE = [set() for _ in range(len(SCC))] for i, e in enumerate(E): for j in e: if I[i] == I[j]: continue # print("i, j, I[i], I[j] =", i, j, I[i], I[j]) nE[I[i]].add(I[j]) iE[I[j]].add(I[i]) nE = [list(e) for e in nE] iE = [list(e) for e in iE] return SCC, I, nE, iE import sys input = lambda: sys.stdin.readline().rstrip() N, M = map(int, input().split()) X = [] for _ in range(M): a, b = map(int, input().split()) X.append((a-1, b-1)) uf = UnionFind(N) for a, b in X: uf.unite(a, b) # G = uf.groups() # print(G) GG, I = uf.groups_index() K = len(GG) D = [{v: f for f, v in enumerate(GG[i])} for i in range(K)] XX = [[] for _ in range(K)] for a, b in X: g = I[uf.root(a)] XX[g].append((D[g][a], D[g][b])) ANS = [] for i in range(K): gg = GG[i] si = len(gg) E = [[] for _ in range(si)] for a, b in XX[i]: E[a].append(b) SCC, II = scc(E) if len(SCC) < si: for j in range(si): ANS.append(str(gg[j-1] + 1) + " " + str(gg[j] + 1)) else: for j in range(si - 1): ANS.append(str(gg[SCC[j][0]] + 1) + " " + str(gg[SCC[j+1][0]] + 1)) print(len(ANS)) print("\n".join(ANS))