結果
問題 | No.1553 Lovely City |
ユーザー |
![]() |
提出日時 | 2023-01-12 00:32:53 |
言語 | PyPy3 (7.3.15) |
結果 |
AC
|
実行時間 | 803 ms / 2,000 ms |
コード長 | 2,341 bytes |
コンパイル時間 | 258 ms |
コンパイル使用メモリ | 81,896 KB |
実行使用メモリ | 154,016 KB |
最終ジャッジ日時 | 2024-12-22 18:06:43 |
合計ジャッジ時間 | 18,277 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 26 |
ソースコード
import sys# sys.setrecursionlimit(1000005)int1 = lambda x: int(x)-1pDB = lambda *x: print(*x, end="\n", file=sys.stderr)p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)def II(): return int(sys.stdin.readline())def LI(): return list(map(int, sys.stdin.readline().split()))def LLI(rows_number): return [LI() for _ in range(rows_number)]def LI1(): return list(map(int1, sys.stdin.readline().split()))def LLI1(rows_number): return [LI1() for _ in range(rows_number)]def SI(): return sys.stdin.readline().rstrip()# dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]inf = (1 << 63)-1# inf = (1 << 31)-1md = 10**9+7# md = 998244353class UnionFind:def __init__(self, n):self.table = [-1]*nself.mem = [[u] for u in range(n)]self.cnt = ndef root(self, u):stack = []while self.table[u] >= 0:stack.append(u)u = self.table[u]for v in stack: self.table[v] = ureturn udef same(self, u, v):return self.root(u) == self.root(v)def merge(self, u, v):u = self.root(u)v = self.root(v)if u == v: return Falsesu = -self.table[u]sv = -self.table[v]if su < sv: u, v = v, uself.table[u] = -su-svself.table[v] = uself.mem[u] += self.mem[v]self.mem[v].clear()self.cnt -= 1return Truedef member(self, u):return self.mem[self.root(u)]# グループの要素数def size(self, u):return -self.table[self.root(u)]n, m = LI()to = [[] for _ in range(n)]deg = [0]*nuf = UnionFind(n)for _ in range(m):u, v = LI1()to[u].append(v)deg[v] += 1uf.merge(u, v)ans = []for uu in uf.mem:if len(uu) == 1: continuetopo = []st = []for u in uu:if deg[u] == 0: st.append(u)while st:u = st.pop()topo.append(u)for v in to[u]:deg[v] -= 1if deg[v] == 0: st.append(v)if len(topo) == len(uu):for i in range(len(topo)-1):ans.append((topo[i], topo[i+1]))else:for i in range(len(uu)):ans.append((uu[i-1], uu[i]))print(len(ans))for u, v in ans: print(u+1, v+1)