結果

問題 No.3309 Aging Railway
コンテスト
ユーザー 👑 loop0919
提出日時 2025-10-24 22:11:27
言語 PyPy3
(7.3.15)
結果
AC  
実行時間 1,405 ms / 3,000 ms
コード長 2,627 bytes
コンパイル時間 340 ms
コンパイル使用メモリ 82,236 KB
実行使用メモリ 262,384 KB
最終ジャッジ日時 2025-10-24 22:11:47
合計ジャッジ時間 19,683 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
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ファイルパターン 結果
other AC * 20
権限があれば一括ダウンロードができます

ソースコード

diff # 

class dsu:
    n = 1
    parent_or_size = [-1 for i in range(n)]

    def __init__(self, N):
        self.n = N
        self.parent_or_size = [-1 for i in range(N)]

    def merge(self, a, b):
        assert 0 <= a < self.n, "0<=a<n,a={0},n={1}".format(a, self.n)
        assert 0 <= b < self.n, "0<=b<n,b={0},n={1}".format(b, self.n)
        x = self.leader(a)
        y = self.leader(b)
        if x == y:
            return x
        if -self.parent_or_size[x] < -self.parent_or_size[y]:
            x, y = y, x
        self.parent_or_size[x] += self.parent_or_size[y]
        self.parent_or_size[y] = x
        return x

    def same(self, a, b):
        assert 0 <= a < self.n, "0<=a<n,a={0},n={1}".format(a, self.n)
        assert 0 <= b < self.n, "0<=b<n,b={0},n={1}".format(b, self.n)
        return self.leader(a) == self.leader(b)

    def leader(self, a):
        assert 0 <= a < self.n, "0<=a<n,a={0},n={1}".format(a, self.n)
        if self.parent_or_size[a] < 0:
            return a
        self.parent_or_size[a] = self.leader(self.parent_or_size[a])
        return self.parent_or_size[a]

    def size(self, a):
        assert 0 <= a < self.n, "0<=a<n,a={0},n={1}".format(a, self.n)
        return -self.parent_or_size[self.leader(a)]

    def groups(self):
        leader_buf = [0 for i in range(self.n)]
        group_size = [0 for i in range(self.n)]
        for i in range(self.n):
            leader_buf[i] = self.leader(i)
            group_size[leader_buf[i]] += 1
        result = [[] for i in range(self.n)]
        for i in range(self.n):
            result[leader_buf[i]].append(i)
        result2 = []
        for i in range(self.n):
            if len(result[i]) > 0:
                result2.append(result[i])
        return result2


N, M = [int(x) for x in input().split()]

edges = []
for _ in range(N - 1):
    u, v = [int(x) - 1 for x in input().split()]
    edges.append((u, v))

people = []
for _ in range(M):
    s, t = [int(x) - 1 for x in input().split()]
    people.append((s, t))

ok, ng = [0] * M, [N - 1] * M

while any(abs(ok[i] - ng[i]) > 1 for i in range(M)):
    mid = [(ok[i] + ng[i]) // 2 for i in range(M)]

    check = [[] for _ in range(N)]
    for i, m in enumerate(mid):
        check[m].append(i)

    uf = dsu(N)

    for idx in range(N - 2, -1, -1):
        u, v = edges[idx]
        uf.merge(u, v)

        for i in check[idx]:
            s, t = people[i]

            if uf.same(s, t):
                ok[i] = idx
            else:
                ng[i] = idx

count = [0] * N
for v in ok:
    count[v] += 1

ans = M
for c in count[:-1]:
    ans -= c
    print(ans)
0