oj.uz

Submission #834597

# Submission time Handle Problem Language Result Execution time Memory
834597 2023-08-22T15:45:20 Z Elias Dynamic Diameter (CEOI19_diameter) C++17
31 / 100
 5000 ms 554552 KB 
#ifndef _DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx") // codeforces
#endif

#include <bits/stdc++.h>

using namespace std;

#define int 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<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, 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, int>>> edges;

	vector<pair<int, int>> aint_edges;

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

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

		aint_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) % int(n - 1);
		e = (e + last) % w;

		auto [a, b] = aint_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:300:20: warning: comparison of integer expressions of different signedness: 'int64_t' {aka 'long int'} and 'std::vector<Tree>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  300 |  for (int i = 0; i < subtrees.size(); i++)
      |                  ~~^~~~~~~~~~~~~~~~~
diameter.cpp: In constructor 'Tree::Tree(std::unordered_map<long int, std::vector<std::pair<long int, 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 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 0 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 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 1 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 0 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 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 23 ms 2644 KB Output is correct
20 Correct 26 ms 2900 KB Output is correct
21 Correct 32 ms 3284 KB Output is correct
22 Correct 35 ms 3924 KB Output is correct
23 Correct 61 ms 13992 KB Output is correct
24 Correct 79 ms 17724 KB Output is correct
25 Correct 90 ms 20020 KB Output is correct
26 Correct 109 ms 23228 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 340 KB Output is correct
5 Correct 47 ms 716 KB Output is correct
6 Correct 0 ms 336 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 72 ms 1044 KB Output is correct
12 Correct 4 ms 3540 KB Output is correct
13 Correct 4 ms 3540 KB Output is correct
14 Correct 6 ms 3540 KB Output is correct
15 Correct 24 ms 3540 KB Output is correct
16 Correct 92 ms 3540 KB Output is correct
17 Correct 82 ms 63352 KB Output is correct
18 Correct 84 ms 63452 KB Output is correct
19 Correct 87 ms 63452 KB Output is correct
20 Correct 110 ms 63360 KB Output is correct
21 Correct 231 ms 63412 KB Output is correct

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 13 ms 3412 KB Output is correct
2 Correct 42 ms 3524 KB Output is correct
3 Correct 185 ms 3724 KB Output is correct
4 Correct 359 ms 4008 KB Output is correct
5 Correct 110 ms 43496 KB Output is correct
6 Correct 172 ms 43648 KB Output is correct
7 Correct 501 ms 43860 KB Output is correct
8 Correct 936 ms 44108 KB Output is correct
9 Correct 691 ms 257324 KB Output is correct
10 Correct 828 ms 257304 KB Output is correct
11 Correct 1438 ms 257648 KB Output is correct
12 Correct 2210 ms 257888 KB Output is correct
13 Correct 1428 ms 548056 KB Output is correct
14 Correct 1603 ms 548168 KB Output is correct
15 Correct 2425 ms 548368 KB Output is correct
16 Correct 3433 ms 548648 KB Output is correct
17 Execution timed out 5047 ms 548660 KB Time limit exceeded
18 Halted 0 ms 0 KB -

Subtask #5
0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 4374 ms 420776 KB Output is correct
2 Correct 4415 ms 435920 KB Output is correct
3 Correct 4234 ms 432440 KB Output is correct
4 Correct 4141 ms 438908 KB Output is correct
5 Correct 4205 ms 405104 KB Output is correct
6 Correct 3238 ms 255392 KB Output is correct
7 Execution timed out 5030 ms 554552 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 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 0 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 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 23 ms 2644 KB Output is correct
20 Correct 26 ms 2900 KB Output is correct
21 Correct 32 ms 3284 KB Output is correct
22 Correct 35 ms 3924 KB Output is correct
23 Correct 61 ms 13992 KB Output is correct
24 Correct 79 ms 17724 KB Output is correct
25 Correct 90 ms 20020 KB Output is correct
26 Correct 109 ms 23228 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 340 KB Output is correct
31 Correct 47 ms 716 KB Output is correct
32 Correct 0 ms 336 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 72 ms 1044 KB Output is correct
38 Correct 4 ms 3540 KB Output is correct
39 Correct 4 ms 3540 KB Output is correct
40 Correct 6 ms 3540 KB Output is correct
41 Correct 24 ms 3540 KB Output is correct
42 Correct 92 ms 3540 KB Output is correct
43 Correct 82 ms 63352 KB Output is correct
44 Correct 84 ms 63452 KB Output is correct
45 Correct 87 ms 63452 KB Output is correct
46 Correct 110 ms 63360 KB Output is correct
47 Correct 231 ms 63412 KB Output is correct
48 Correct 13 ms 3412 KB Output is correct
49 Correct 42 ms 3524 KB Output is correct
50 Correct 185 ms 3724 KB Output is correct
51 Correct 359 ms 4008 KB Output is correct
52 Correct 110 ms 43496 KB Output is correct
53 Correct 172 ms 43648 KB Output is correct
54 Correct 501 ms 43860 KB Output is correct
55 Correct 936 ms 44108 KB Output is correct
56 Correct 691 ms 257324 KB Output is correct
57 Correct 828 ms 257304 KB Output is correct
58 Correct 1438 ms 257648 KB Output is correct
59 Correct 2210 ms 257888 KB Output is correct
60 Correct 1428 ms 548056 KB Output is correct
61 Correct 1603 ms 548168 KB Output is correct
62 Correct 2425 ms 548368 KB Output is correct
63 Correct 3433 ms 548648 KB Output is correct
64 Execution timed out 5047 ms 548660 KB Time limit exceeded
65 Halted 0 ms 0 KB -