結果
問題 | No.1865 Make Cycle |
ユーザー | aaaaaaaaaa2230 |
提出日時 | 2022-03-04 22:00:28 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 1,021 ms / 3,000 ms |
コード長 | 2,866 bytes |
コンパイル時間 | 382 ms |
コンパイル使用メモリ | 87,312 KB |
実行使用メモリ | 291,756 KB |
最終ジャッジ日時 | 2023-09-26 01:00:47 |
合計ジャッジ時間 | 17,324 ms |
ジャッジサーバーID (参考情報) |
judge15 / judge12 |
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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 | 706 ms
223,352 KB |
testcase_01 | AC | 506 ms
170,300 KB |
testcase_02 | AC | 752 ms
249,628 KB |
testcase_03 | AC | 457 ms
188,324 KB |
testcase_04 | AC | 697 ms
267,256 KB |
testcase_05 | AC | 818 ms
283,588 KB |
testcase_06 | AC | 746 ms
245,380 KB |
testcase_07 | AC | 650 ms
227,924 KB |
testcase_08 | AC | 861 ms
291,756 KB |
testcase_09 | AC | 762 ms
283,000 KB |
testcase_10 | AC | 830 ms
290,348 KB |
testcase_11 | AC | 725 ms
264,056 KB |
testcase_12 | AC | 639 ms
215,060 KB |
testcase_13 | AC | 665 ms
215,868 KB |
testcase_14 | AC | 576 ms
192,436 KB |
testcase_15 | AC | 820 ms
273,540 KB |
testcase_16 | AC | 885 ms
288,684 KB |
testcase_17 | AC | 599 ms
207,092 KB |
testcase_18 | AC | 864 ms
286,328 KB |
testcase_19 | AC | 1,021 ms
286,052 KB |
testcase_20 | AC | 65 ms
71,288 KB |
testcase_21 | AC | 65 ms
71,272 KB |
testcase_22 | AC | 65 ms
71,544 KB |
testcase_23 | AC | 65 ms
71,132 KB |
ソースコード
import sys input = sys.stdin.readline class SCC: def __init__(self,n): self.n = n self.edges = [] def csr(self): self.start = [0]*(self.n+1) self.elist = [0]*len(self.edges) for e in self.edges: self.start[e[0]+1] += 1 for i in range(1,self.n+1): self.start[i] += self.start[i-1] counter = self.start[:] for e in self.edges: self.elist[counter[e[0]]] = e[1] counter[e[0]] += 1 def add_edge(self,u,v): self.edges.append((u,v)) def scc_ids(self): self.csr() n = self.n now_ord = group_num = 0 visited = [] low = [0]*n order = [-1]*n ids = [0]*n parent = [-1]*n stack = [] for i in range(n): if order[i] == -1: stack.append(i) stack.append(i) while stack: v = stack.pop() if order[v] == -1: low[v] = order[v] = now_ord now_ord += 1 visited.append(v) for i in range(self.start[v],self.start[v+1]): to = self.elist[i] if order[to] == -1: stack.append(to) stack.append(to) parent[to] = v else: low[v] = min(low[v],order[to]) else: if low[v] == order[v]: while True: u = visited.pop() order[u] = n ids[u] = group_num if u == v: break group_num += 1 if parent[v] != -1: low[parent[v]] = min(low[parent[v]],low[v]) for i,x in enumerate(ids): ids[i] = group_num-1-x return group_num,ids def scc(self): group_num,ids = self.scc_ids() groups = [[] for i in range(group_num)] for i,x in enumerate(ids): groups[x].append(i) return groups n,q = map(int,input().split()) edges = [[int(x)-1 for x in input().split()] for i in range(q)] def search(x): scc = SCC(n) for i in range(x): a,b = edges[i] scc.add_edge(a,b) groups = scc.scc() for g in groups: if len(g) > 1: return True return False l = 0 r = q+1 while r > l + 1: m = (r+l)//2 if search(m): r = m else: l = m if l == q: if search(l): print(q) else: print(-1) else: print(r)