oj.uz

Submission #834594

# Submission time Handle Problem Language Result Execution time Memory
834594 2023-08-22T15:42:42 Z Elias Dynamic Diameter (CEOI19_diameter) C++17
31 / 100
 5000 ms 535432 KB 
#ifndef _DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif

#include <bits/stdc++.h>

using namespace std;

#define all(x) (x).begin(), (x).end()

#define ll int64_t

template <class T>
istream &operator>>(istream &in, vector<T> &a)
{
	for (T &x : a)
		in >> x;
	return in;
}

template <class T>
ostream &operator<<(ostream &out, const vector<T> &a)
{
	for (T x : a)
		out << x << " ";
	out << "\n";
	return out;
}

struct SegTree
{
	pair<ll, int> get(int l, int r)
	{
		return get(0, n, 0, l, r);
	}
	void inc(int l, int r, int x)
	{
		inc(0, n, 0, l, r, x);
	}

	SegTree(const vector<ll> &a)
	{
		n = a.size();
		updates = vector<ll>(4 * n);
		b = vector<pair<ll, int>>(4 * n);
		build(0, n, 0, a);
	}

	SegTree() {}

private:
	int n = 0;
	vector<pair<ll, int>> b = {};
	vector<ll> updates = {};

	void push(int l, int r, int i)
	{
		if (l + 1 == r)
			return;
		updates[i * 2 + 1] += updates[i];
		updates[i * 2 + 2] += updates[i];
		b[i * 2 + 1].first += updates[i];
		b[i * 2 + 2].first += updates[i];
		updates[i] = 0;
	}

	pair<ll, int> build(int l, int r, int i, const vector<ll> &a)
	{
		if (l + 1 == r)
			return b[i] = pair<ll, int>{a[l], l};
		int m = (l + r) / 2;
		return b[i] = max(build(l, m, i * 2 + 1, a), build(m, r, i * 2 + 2, a));
	}

	pair<ll, int> get(int l, int r, int i, int ql, int qr)
	{
		if (l >= qr || r <= ql)
			return {LLONG_MIN / 2, -1};
		if (l >= ql && r <= qr)
			return b[i];
		push(l, r, i);
		int m = (l + r) / 2;
		return max(get(l, m, i * 2 + 1, ql, qr), get(m, r, i * 2 + 2, ql, qr));
	}

	pair<ll, int> inc(int l, int r, int i, int ul, int ur, int x)
	{
		if (l >= ur || r <= ul)
			return b[i];
		if (l >= ul && r <= ur)
		{
			updates[i] += x;
			b[i].first += x;
			return b[i];
		}
		push(l, r, i);
		int m = (l + r) / 2;
		return b[i] = max(inc(l, m, i * 2 + 1, ul, ur, x), inc(m, r, i * 2 + 2, ul, ur, x));
	}
};

struct Tree
{
	int n;

	unordered_map<int, vector<pair<int, ll>>> edges;

	unordered_map<int, int> pre;
	unordered_map<int, int> subtree;
	unordered_map<int, int> initial_parent;
	vector<int> pre_order;

	vector<ll> pre_dist;

	int timer = 0;
	int centroid = -1;

	SegTree pre_dist_seg;

	int find_centroid(int i, int p = -1)
	{
		int subtree_size = 1;
		int largest_subtree = 0;

		for (auto [c, D] : edges[i])
		{
			if (c != p)
			{
				int sub = find_centroid(c, i);
				subtree_size += sub;
				largest_subtree = max(largest_subtree, sub);
			}
		}

		if (largest_subtree <= n / 2 && n - subtree_size <= n / 2)
			centroid = i;

		return subtree_size;
	}

	void get_edges(int i, int p, unordered_map<int, vector<pair<int, ll>>> &out)
	{
		for (auto [c, d] : edges[i])
		{
			if (c == centroid)
				continue;
			out[i].push_back({c, d});
			if (c != p)
				get_edges(c, i, out);
		}
	}

	int dfs(int i, ll d = 0, int p = -1)
	{
		pre[i] = timer++;
		pre_order.push_back(i);
		pre_dist[pre[i]] = d;

		int subtree_size = 1;

		if (p == -1)
			initial_parent[i] = -1;
		else if (initial_parent[p] == -1)
			initial_parent[i] = i;
		else
			initial_parent[i] = initial_parent[p];

		for (auto [c, D] : edges[i])
		{
			if (c != p)
			{
				subtree_size += dfs(c, d + D, i);
			}
		}

		subtree[i] = subtree_size;

		return subtree_size;
	}

	vector<unordered_map<int, vector<pair<int, ll>>>> split()
	{
		vector<unordered_map<int, vector<pair<int, ll>>>> out;
		for (auto [c, d] : edges[centroid])
		{
			unordered_map<int, vector<pair<int, ll>>> subset;
			get_edges(c, centroid, subset);
			out.push_back(move(subset));
		}
		return out;
	}

	Tree(unordered_map<int, vector<pair<int, ll>>> edges) : edges{edges}
	{
		n = edges.size();
		pre_dist = vector<ll>(n);

		int start;

		for (auto [i, c] : edges)
		{
			start = i;
			break;
		}

		find_centroid(start);

		assert(centroid != -1);

		dfs(centroid);

		pre_dist_seg = SegTree(pre_dist);
	}

	ll update(int a, int b, int c)
	{
		if (subtree.count(a) != 0 && subtree.count(b) != 0)
		{
			if (pre[a] > pre[b])
				swap(a, b);

			ll dist_lower = pre_dist_seg.get(pre[b], pre[b] + 1).first;
			ll dist_upper = pre_dist_seg.get(pre[a], pre[a] + 1).first;

			ll old_weight = dist_lower - dist_upper;

			ll delta = c - old_weight;
			pre_dist_seg.inc(pre[b], pre[b] + subtree[b], delta);
		}

		auto [dist, i] = pre_dist_seg.get(0, n);
		int bad_child = initial_parent[pre_order[i]];

		auto dist2 = pre_dist_seg.get(0, pre[bad_child]).first;
		auto dist3 = pre_dist_seg.get(pre[bad_child] + subtree[bad_child], n).first;

		return dist + max({dist2, dist3, 0l});
	}
};

signed main()
{
	cin.tie(0);
	ios_base::sync_with_stdio(false);

	int n, q, w;
	cin >> n >> q >> w;

	unordered_map<int, vector<pair<int, ll>>> edges;

	vector<pair<int, int>> all_edges;

	for (int i = 0; i < n - 1; i++)
	{
		int a, b;
		ll c;
		cin >> a >> b >> c;
		a--, b--;

		edges[a].push_back({b, c});
		edges[b].push_back({a, c});

		all_edges.push_back({a, b});
	}

	vector<Tree> subtrees;
	subtrees.push_back(Tree(edges));

	queue<int> todo;
	todo.push(0);

	vector<vector<int>> trees_using(n, {0});

	while (todo.size())
	{
		int index = todo.front();
		todo.pop();

		auto out = subtrees[index].split();
		for (auto &x : out)
		{
			if (x.size() > 1)
			{
				int new_index = subtrees.size();
				todo.push(new_index);
				subtrees.push_back(Tree(x));
				for (auto [i, c] : x)
				{
					if (trees_using[i].back() != new_index)
						trees_using[i].push_back(new_index);
				}
			}
		}
	}

	vector<ll> subtree_result(subtrees.size());

	set<pair<ll, int>> results;

	for (int i = 0; i < subtrees.size(); i++)
	{
		subtree_result[i] = subtrees[i].update(-1, -1, -1);
		results.insert({subtree_result[i], i});
	}

	ll last = 0;

	while (q--)
	{
		ll d, e;
		cin >> d >> e;
		d = (d + last) % ll(n - 1);
		e = (e + last) % w;

		auto [a, b] = all_edges[d];

		ll out = 0;

		for (int i : trees_using[a])
		{
			results.erase({subtree_result[i], i});
			subtree_result[i] = subtrees[i].update(a, b, e);
			results.insert({subtree_result[i], i});
		}

		out = prev(results.end())->first;

		cout << out << "\n";
		last = out;
	}
}

Compilation message

diameter.cpp: In function 'int main()':
diameter.cpp:301:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Tree>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  301 |  for (int i = 0; i < subtrees.size(); i++)
      |                  ~~^~~~~~~~~~~~~~~~~
diameter.cpp: In constructor 'Tree::Tree(std::unordered_map<int, std::vector<std::pair<int, long int> > >)':
diameter.cpp:207:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
  207 |   find_centroid(start);
      |   ~~~~~~~~~~~~~^~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct

Subtask #2
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 25 ms 2516 KB Output is correct
20 Correct 26 ms 2772 KB Output is correct
21 Correct 35 ms 3156 KB Output is correct
22 Correct 35 ms 3788 KB Output is correct
23 Correct 61 ms 13512 KB Output is correct
24 Correct 78 ms 17128 KB Output is correct
25 Correct 91 ms 19404 KB Output is correct
26 Correct 121 ms 22580 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 2 ms 340 KB Output is correct
4 Correct 10 ms 340 KB Output is correct
5 Correct 48 ms 724 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 596 KB Output is correct
8 Correct 1 ms 596 KB Output is correct
9 Correct 2 ms 596 KB Output is correct
10 Correct 15 ms 724 KB Output is correct
11 Correct 71 ms 976 KB Output is correct
12 Correct 5 ms 3412 KB Output is correct
13 Correct 4 ms 3412 KB Output is correct
14 Correct 7 ms 3412 KB Output is correct
15 Correct 29 ms 3412 KB Output is correct
16 Correct 102 ms 3468 KB Output is correct
17 Correct 91 ms 62276 KB Output is correct
18 Correct 89 ms 62176 KB Output is correct
19 Correct 96 ms 62316 KB Output is correct
20 Correct 115 ms 62276 KB Output is correct
21 Correct 223 ms 62276 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 9 ms 3284 KB Output is correct
2 Correct 42 ms 3428 KB Output is correct
3 Correct 182 ms 3596 KB Output is correct
4 Correct 345 ms 3884 KB Output is correct
5 Correct 108 ms 42536 KB Output is correct
6 Correct 173 ms 42324 KB Output is correct
7 Correct 471 ms 42664 KB Output is correct
8 Correct 856 ms 42884 KB Output is correct
9 Correct 658 ms 250840 KB Output is correct
10 Correct 786 ms 251008 KB Output is correct
11 Correct 1380 ms 251236 KB Output is correct
12 Correct 2145 ms 251488 KB Output is correct
13 Correct 1451 ms 534928 KB Output is correct
14 Correct 1743 ms 534960 KB Output is correct
15 Correct 2286 ms 535176 KB Output is correct
16 Correct 3231 ms 535392 KB Output is correct
17 Execution timed out 5033 ms 535432 KB Time limit exceeded
18 Halted 0 ms 0 KB -

Subtask #5
0 / 24.0

# Verdict Execution time Memory Grader output
1 Runtime error 133 ms 134248 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 468 KB Output is correct
15 Correct 1 ms 468 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 25 ms 2516 KB Output is correct
20 Correct 26 ms 2772 KB Output is correct
21 Correct 35 ms 3156 KB Output is correct
22 Correct 35 ms 3788 KB Output is correct
23 Correct 61 ms 13512 KB Output is correct
24 Correct 78 ms 17128 KB Output is correct
25 Correct 91 ms 19404 KB Output is correct
26 Correct 121 ms 22580 KB Output is correct
27 Correct 0 ms 212 KB Output is correct
28 Correct 0 ms 212 KB Output is correct
29 Correct 2 ms 340 KB Output is correct
30 Correct 10 ms 340 KB Output is correct
31 Correct 48 ms 724 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 596 KB Output is correct
34 Correct 1 ms 596 KB Output is correct
35 Correct 2 ms 596 KB Output is correct
36 Correct 15 ms 724 KB Output is correct
37 Correct 71 ms 976 KB Output is correct
38 Correct 5 ms 3412 KB Output is correct
39 Correct 4 ms 3412 KB Output is correct
40 Correct 7 ms 3412 KB Output is correct
41 Correct 29 ms 3412 KB Output is correct
42 Correct 102 ms 3468 KB Output is correct
43 Correct 91 ms 62276 KB Output is correct
44 Correct 89 ms 62176 KB Output is correct
45 Correct 96 ms 62316 KB Output is correct
46 Correct 115 ms 62276 KB Output is correct
47 Correct 223 ms 62276 KB Output is correct
48 Correct 9 ms 3284 KB Output is correct
49 Correct 42 ms 3428 KB Output is correct
50 Correct 182 ms 3596 KB Output is correct
51 Correct 345 ms 3884 KB Output is correct
52 Correct 108 ms 42536 KB Output is correct
53 Correct 173 ms 42324 KB Output is correct
54 Correct 471 ms 42664 KB Output is correct
55 Correct 856 ms 42884 KB Output is correct
56 Correct 658 ms 250840 KB Output is correct
57 Correct 786 ms 251008 KB Output is correct
58 Correct 1380 ms 251236 KB Output is correct
59 Correct 2145 ms 251488 KB Output is correct
60 Correct 1451 ms 534928 KB Output is correct
61 Correct 1743 ms 534960 KB Output is correct
62 Correct 2286 ms 535176 KB Output is correct
63 Correct 3231 ms 535392 KB Output is correct
64 Execution timed out 5033 ms 535432 KB Time limit exceeded
65 Halted 0 ms 0 KB -