結果
問題 | No.1553 Lovely City |
ユーザー |
|
提出日時 | 2021-06-19 15:53:27 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 834 ms / 2,000 ms |
コード長 | 1,709 bytes |
コンパイル時間 | 383 ms |
コンパイル使用メモリ | 82,424 KB |
実行使用メモリ | 137,428 KB |
最終ジャッジ日時 | 2024-06-22 22:07:07 |
合計ジャッジ時間 | 19,721 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge2 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 26 |
ソースコード
from collections import dequeclass Unionfind:def __init__(self,n):self.uf = [-1]*ndef find(self,x):if self.uf[x] < 0:return xelse:self.uf[x] = self.find(self.uf[x])return self.uf[x]def same(self,x,y):return self.find(x) == self.find(y)def union(self,x,y):x = self.find(x)y = self.find(y)if x == y:return Falseif self.uf[x] > self.uf[y]:x,y = y,xself.uf[x] += self.uf[y]self.uf[y] = xreturn Truedef size(self,x):x = self.find(x)return -self.uf[x]n,m = map(int,input().split())uf = Unionfind(n+1)e = [[] for i in range(n+1)]deg = [0]*(n+1)use = [0]*(n+1)for _ in range(m):u,v = map(int,input().split())e[u].append(v)uf.union(u,v)use[u] = 1use[v] = 1deg[v] += 1group = [[] for i in range(n+1)]for i in range(n+1):if use[i]:group[uf.find(i)].append(i)ans = []for i in range(n+1):if group[i] == []:continueq = deque([])loop = 0for ind in group[i]:if deg[ind]:continueq.append(ind)order = []while q:now = q.pop()order.append(now)for nex in e[now]:deg[nex] -= 1if deg[nex] == 0:q.append(nex)if len(order) == len(group[i]):for x,y in zip(order,order[1:]):ans.append((x,y))else:for j in range(len(group[i])):x = group[i][j]y = group[i][(j+1)%len(group[i])]ans.append((x,y))print(len(ans))for x,y in ans:print(x,y)