oj.uz

Submission #834576

# Submission time Handle Problem Language Result Execution time Memory
834576 2023-08-22T15:29:30 Z Elias Dynamic Diameter (CEOI19_diameter) C++17
31 / 100
 5000 ms 553844 KB 
#ifndef _DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#endif

#include <bits/stdc++.h>

using namespace std;

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

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

	SegTree() {}

private:
	int n = 0;
	vector<pair<int, int>> b = {};
	vector<int> 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<int, int> build(int l, int r, int i, const vector<int> &a)
	{
		if (l + 1 == r)
			return b[i] = pair<int, 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<int, 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<int, 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, int>>> edges;

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

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

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

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

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

			int old_weight = dist_lower - dist_upper;

			int 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, 0ll});
	}
};

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, int>>> edges;

	vector<pair<int, int>> all_edges;

	for (int i = 0; i < n - 1; i++)
	{
		int a, b, 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<int> subtree_result(subtrees.size());

	set<pair<int, 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});
	}

	int last = 0;

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

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

		int 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:299:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<Tree>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  299 |  for (int i = 0; i < subtrees.size(); i++)
      |                  ~~^~~~~~~~~~~~~~~~~
diameter.cpp: In constructor 'Tree::Tree(std::unordered_map<long long int, std::vector<std::pair<long long int, long long int> > >)':
diameter.cpp:206:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
  206 |   find_centroid(start);
      |   ~~~~~~~~~~~~~^~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 340 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 320 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 2 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 448 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 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 340 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 320 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 2 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 448 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 30 ms 2728 KB Output is correct
20 Correct 28 ms 2900 KB Output is correct
21 Correct 35 ms 3284 KB Output is correct
22 Correct 42 ms 3972 KB Output is correct
23 Correct 65 ms 14140 KB Output is correct
24 Correct 131 ms 17780 KB Output is correct
25 Correct 101 ms 20148 KB Output is correct
26 Correct 115 ms 23356 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 2 ms 332 KB Output is correct
4 Correct 13 ms 528 KB Output is correct
5 Correct 62 ms 1396 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 596 KB Output is correct
8 Correct 2 ms 596 KB Output is correct
9 Correct 2 ms 596 KB Output is correct
10 Correct 23 ms 840 KB Output is correct
11 Correct 80 ms 1868 KB Output is correct
12 Correct 5 ms 3540 KB Output is correct
13 Correct 5 ms 3540 KB Output is correct
14 Correct 7 ms 3544 KB Output is correct
15 Correct 24 ms 3668 KB Output is correct
16 Correct 117 ms 4576 KB Output is correct
17 Correct 95 ms 64628 KB Output is correct
18 Correct 97 ms 64640 KB Output is correct
19 Correct 100 ms 64664 KB Output is correct
20 Correct 135 ms 64816 KB Output is correct
21 Correct 279 ms 64780 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 3508 KB Output is correct
2 Correct 42 ms 3596 KB Output is correct
3 Correct 193 ms 4064 KB Output is correct
4 Correct 369 ms 4820 KB Output is correct
5 Correct 103 ms 43688 KB Output is correct
6 Correct 198 ms 43876 KB Output is correct
7 Correct 525 ms 44504 KB Output is correct
8 Correct 1004 ms 45268 KB Output is correct
9 Correct 731 ms 258124 KB Output is correct
10 Correct 872 ms 258284 KB Output is correct
11 Correct 1558 ms 258944 KB Output is correct
12 Correct 2349 ms 259732 KB Output is correct
13 Correct 1587 ms 549636 KB Output is correct
14 Correct 1735 ms 549784 KB Output is correct
15 Correct 2557 ms 550552 KB Output is correct
16 Correct 3583 ms 551392 KB Output is correct
17 Execution timed out 5043 ms 551060 KB Time limit exceeded
18 Halted 0 ms 0 KB -

Subtask #5
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 4688 ms 422656 KB Output is correct
2 Correct 4625 ms 435948 KB Output is correct
3 Correct 4753 ms 432560 KB Output is correct
4 Correct 4382 ms 438844 KB Output is correct
5 Correct 4712 ms 405056 KB Output is correct
6 Correct 3721 ms 255240 KB Output is correct
7 Execution timed out 5092 ms 553844 KB Time limit exceeded
8 Halted 0 ms 0 KB -

Subtask #6
0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 340 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 320 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 2 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 448 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 30 ms 2728 KB Output is correct
20 Correct 28 ms 2900 KB Output is correct
21 Correct 35 ms 3284 KB Output is correct
22 Correct 42 ms 3972 KB Output is correct
23 Correct 65 ms 14140 KB Output is correct
24 Correct 131 ms 17780 KB Output is correct
25 Correct 101 ms 20148 KB Output is correct
26 Correct 115 ms 23356 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 2 ms 332 KB Output is correct
30 Correct 13 ms 528 KB Output is correct
31 Correct 62 ms 1396 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 1 ms 596 KB Output is correct
34 Correct 2 ms 596 KB Output is correct
35 Correct 2 ms 596 KB Output is correct
36 Correct 23 ms 840 KB Output is correct
37 Correct 80 ms 1868 KB Output is correct
38 Correct 5 ms 3540 KB Output is correct
39 Correct 5 ms 3540 KB Output is correct
40 Correct 7 ms 3544 KB Output is correct
41 Correct 24 ms 3668 KB Output is correct
42 Correct 117 ms 4576 KB Output is correct
43 Correct 95 ms 64628 KB Output is correct
44 Correct 97 ms 64640 KB Output is correct
45 Correct 100 ms 64664 KB Output is correct
46 Correct 135 ms 64816 KB Output is correct
47 Correct 279 ms 64780 KB Output is correct
48 Correct 10 ms 3508 KB Output is correct
49 Correct 42 ms 3596 KB Output is correct
50 Correct 193 ms 4064 KB Output is correct
51 Correct 369 ms 4820 KB Output is correct
52 Correct 103 ms 43688 KB Output is correct
53 Correct 198 ms 43876 KB Output is correct
54 Correct 525 ms 44504 KB Output is correct
55 Correct 1004 ms 45268 KB Output is correct
56 Correct 731 ms 258124 KB Output is correct
57 Correct 872 ms 258284 KB Output is correct
58 Correct 1558 ms 258944 KB Output is correct
59 Correct 2349 ms 259732 KB Output is correct
60 Correct 1587 ms 549636 KB Output is correct
61 Correct 1735 ms 549784 KB Output is correct
62 Correct 2557 ms 550552 KB Output is correct
63 Correct 3583 ms 551392 KB Output is correct
64 Execution timed out 5043 ms 551060 KB Time limit exceeded
65 Halted 0 ms 0 KB -