Submission #1289172

#	Time	Username	Problem	Language	Result	Execution time	Memory
1289172		thieunguyenhuy	Meetings 2 (JOI21_meetings2)	C++20	100 / 100	310 ms	49068 KiB

meetings2

#include <bits/stdc++.h>
using namespace std;

#define POPCOUNT(n) (__builtin_popcountll((n)))
#define CLZ(n) (__builtin_clzll((n)))
#define CTZ(n) (__builtin_ctzll((n)))
#define LOG(n) (63 - __builtin_clzll((n)))
#define BIT(n, i) (((n) >> (i)) & 1ll)
#define MASK(i) (1ll << (i))
#define FLIP(n, i) ((n) ^ (1ll << (i)))
#define ON(n, i) ((n) | MASK(i))
#define OFF(n, i) ((n) & ~MASK(i))

#define Int __int128
#define fi first
#define se second

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long long, int> pli;
typedef pair<int, long long> pil;
typedef vector<pair<int, int>> vii;
typedef vector<pair<long long, long long>> vll;
typedef vector<pair<long long, int>> vli;
typedef vector<pair<int, long long>> vil;

template <class T1, class T2> bool maximize(T1 &x, T2 y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
template <class T1, class T2> bool minimize(T1 &x, T2 y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}

template <class T> void remove_duplicate(vector<T> &ve) {
    sort (ve.begin(), ve.end());
    ve.resize(unique(ve.begin(), ve.end()) - ve.begin());
}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
long long random(long long l, long long r) {
    return uniform_int_distribution<long long>(l, r)(rng);
}
unsigned long long random(unsigned long long l, unsigned long long r) {
    return uniform_int_distribution<unsigned long long>(l, r)(rng);
}
template <class T> T random(T r) {
    return rng() % r;
}

const int N = 2e5 + 5, LG = 18;
const int MOD = 1e9 + 7;
const int inf = 1e9;
const long long INF = 1e18;

int n;
int ans[N], sz[N], dep[N], up[N][LG];
vector<int> adj[N];

struct Edge {
	int mi, u, v;

	Edge(int _mi = 0, int _u = 0, int _v = 0) {
		mi = _mi, u = _u, v = _v;
	}
};
vector<Edge> edges;

void dfs(int u, int fa) {
	sz[u] = 1;
	for (auto v : adj[u]) if (v != fa) {
		up[v][0] = u, dep[v] = dep[u] + 1;
		for (int i = 1; i < LG; ++i)
			up[v][i] = up[up[v][i - 1]][i - 1];
		dfs(v, u);
		edges.emplace_back(min(sz[v], n - sz[v]), u, v);
		sz[u] += sz[v];
	}
}

int lca(int u, int v) {
	if (dep[u] < dep[v]) swap(u, v);
	int delta = dep[u] - dep[v];
	for (int i = 0; MASK(i) <= delta; ++i) 
		if (BIT(delta, i)) u = up[u][i];
	if (u == v) return u;
	for (int i = LOG(dep[u]); i >= 0; --i)
		if (up[u][i] != up[v][i]) {
			u = up[u][i], v = up[v][i];
		}
	return up[u][0];
}

int getDist(int u, int v) {
	return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}

struct DSU {
	vector<int> lab;
	vector<int> A, B;
	int diameter = 0;

	DSU(int n) {
		lab.assign(n + 1, -1); diameter = 0;
		A.assign(n + 1, 0), B.assign(n + 1, 0);
		for (int i = 1; i <= n; ++i) A[i] = B[i] = i;
	}

	int find_set(int p) {
		return (lab[p] < 0 ? p : lab[p] = find_set(lab[p]));
	}

	bool join(int x, int y) {
		int u = find_set(x), v = find_set(y);
		if (u != v) {
			if (lab[u] > lab[v]) {
				swap(u, v);
				swap(x, y);
			}
			if (getDist(x, A[u]) < getDist(x, B[u])) swap(A[u], B[u]);
			if (getDist(y, A[v]) < getDist(y, B[v])) swap(A[v], B[v]);
		
			if (getDist(A[u], B[u]) < getDist(A[v], B[v]))
				A[u] = A[v], B[u] = B[v];
			if (getDist(A[u], x) + 1 + getDist(y, A[v]) > getDist(A[u], B[u]))
				B[u] = A[v];

			maximize(diameter, getDist(A[u], B[u]));
			lab[u] += lab[v], lab[v] = u;
			return true;
		}
		return false;
	}
};

signed main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);

    cin >> n;

    for (int i = 1; i < n; ++i) {
    	int u, v; cin >> u >> v;
    	adj[u].emplace_back(v), adj[v].emplace_back(u);
    }

    dfs(1, -1);

    for (int k = 1; k <= n; ++k) ans[k] = 1;

    sort (edges.begin(), edges.end(), [&](Edge x, Edge y) {
    	return x.mi > y.mi;
    });

	int p = -1; DSU dsu(n);
	for (int k = n / 2; k > 0; --k) {
		while (p + 1 < edges.size() && edges[p + 1].mi == k) {
			auto [_, u, v] = edges[++p];
			dsu.join(u, v);
		}
		ans[k * 2] = 1 + dsu.diameter;
	}

    for (int k = 1; k <= n; ++k) cout << ans[k] << '\n';
    return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 16 / 16
• Subtask 3: 80 / 80