oj.uz

Submission #834589

# Submission time Handle Problem Language Result Execution time Memory
834589 2023-08-22T15:36:33 Z Elias Dynamic Diameter (CEOI19_diameter) C++17
49 / 100
 4526 ms 442812 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()

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, 0});
	}
};

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:298:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Tree>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  298 |  for (int i = 0; i < subtrees.size(); i++)
      |                  ~~^~~~~~~~~~~~~~~~~
diameter.cpp: In constructor 'Tree::Tree(std::unordered_map<int, std::vector<std::pair<int, int> > >)':
diameter.cpp:205:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
  205 |   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 340 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 316 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 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 320 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 592 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 2 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 340 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 316 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 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 320 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 592 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 2 ms 468 KB Output is correct
19 Correct 23 ms 2252 KB Output is correct
20 Correct 28 ms 2516 KB Output is correct
21 Correct 31 ms 2772 KB Output is correct
22 Correct 34 ms 3256 KB Output is correct
23 Correct 57 ms 11712 KB Output is correct
24 Correct 73 ms 14664 KB Output is correct
25 Correct 96 ms 16636 KB Output is correct
26 Correct 93 ms 18828 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 1 ms 340 KB Output is correct
4 Correct 10 ms 468 KB Output is correct
5 Correct 49 ms 1412 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 17 ms 848 KB Output is correct
11 Correct 73 ms 1916 KB Output is correct
12 Correct 4 ms 3284 KB Output is correct
13 Correct 4 ms 3284 KB Output is correct
14 Correct 6 ms 3284 KB Output is correct
15 Correct 23 ms 3412 KB Output is correct
16 Correct 94 ms 4244 KB Output is correct
17 Correct 81 ms 56808 KB Output is correct
18 Correct 80 ms 56828 KB Output is correct
19 Correct 83 ms 56824 KB Output is correct
20 Correct 108 ms 56980 KB Output is correct
21 Correct 238 ms 56912 KB Output is correct

Subtask #4
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 2900 KB Output is correct
2 Correct 45 ms 3020 KB Output is correct
3 Correct 176 ms 3540 KB Output is correct
4 Correct 348 ms 4308 KB Output is correct
5 Correct 93 ms 35132 KB Output is correct
6 Correct 166 ms 35436 KB Output is correct
7 Correct 481 ms 35884 KB Output is correct
8 Correct 770 ms 36664 KB Output is correct
9 Correct 542 ms 207440 KB Output is correct
10 Correct 690 ms 207724 KB Output is correct
11 Correct 1219 ms 208272 KB Output is correct
12 Correct 1853 ms 208896 KB Output is correct
13 Correct 1181 ms 441252 KB Output is correct
14 Correct 1330 ms 441404 KB Output is correct
15 Correct 2019 ms 441796 KB Output is correct
16 Correct 2911 ms 441868 KB Output is correct
17 Correct 4526 ms 442812 KB Output is correct

Subtask #5
0 / 24.0

# Verdict Execution time Memory Grader output
1 Runtime error 116 ms 109036 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 1 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 316 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 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 320 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 592 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 2 ms 468 KB Output is correct
19 Correct 23 ms 2252 KB Output is correct
20 Correct 28 ms 2516 KB Output is correct
21 Correct 31 ms 2772 KB Output is correct
22 Correct 34 ms 3256 KB Output is correct
23 Correct 57 ms 11712 KB Output is correct
24 Correct 73 ms 14664 KB Output is correct
25 Correct 96 ms 16636 KB Output is correct
26 Correct 93 ms 18828 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 10 ms 468 KB Output is correct
31 Correct 49 ms 1412 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 17 ms 848 KB Output is correct
37 Correct 73 ms 1916 KB Output is correct
38 Correct 4 ms 3284 KB Output is correct
39 Correct 4 ms 3284 KB Output is correct
40 Correct 6 ms 3284 KB Output is correct
41 Correct 23 ms 3412 KB Output is correct
42 Correct 94 ms 4244 KB Output is correct
43 Correct 81 ms 56808 KB Output is correct
44 Correct 80 ms 56828 KB Output is correct
45 Correct 83 ms 56824 KB Output is correct
46 Correct 108 ms 56980 KB Output is correct
47 Correct 238 ms 56912 KB Output is correct
48 Correct 12 ms 2900 KB Output is correct
49 Correct 45 ms 3020 KB Output is correct
50 Correct 176 ms 3540 KB Output is correct
51 Correct 348 ms 4308 KB Output is correct
52 Correct 93 ms 35132 KB Output is correct
53 Correct 166 ms 35436 KB Output is correct
54 Correct 481 ms 35884 KB Output is correct
55 Correct 770 ms 36664 KB Output is correct
56 Correct 542 ms 207440 KB Output is correct
57 Correct 690 ms 207724 KB Output is correct
58 Correct 1219 ms 208272 KB Output is correct
59 Correct 1853 ms 208896 KB Output is correct
60 Correct 1181 ms 441252 KB Output is correct
61 Correct 1330 ms 441404 KB Output is correct
62 Correct 2019 ms 441796 KB Output is correct
63 Correct 2911 ms 441868 KB Output is correct
64 Correct 4526 ms 442812 KB Output is correct
65 Runtime error 116 ms 109036 KB Execution killed with signal 6
66 Halted 0 ms 0 KB -