oj.uz

Submission #834515

# Submission time Handle Problem Language Result Execution time Memory
834515 2023-08-22T15:09:20 Z Elias Dynamic Diameter (CEOI19_diameter) C++17
24 / 100
 5000 ms 427780 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
{
	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();
		b = updates = vector<int>(4 * n);
		build(0, n, 0, a);
	}

	SegTree() {}

private:
	int n = 0;
	vector<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] += updates[i];
		b[i * 2 + 2] += updates[i];
		updates[i] = 0;
	}

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

	int get(int l, int r, int i, int ql, int qr)
	{
		if (l >= qr || r <= ql)
			return LLONG_MIN / 2;
		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));
	}

	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] += 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;

	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_dist[pre[i]] = d;

		int subtree_size = 1;

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

			int old_weight = dist_lower - dist_upper;

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

		int largest = 0;
		int second = 0;

		for (auto [c, d] : edges[centroid])
		{
			int dist = pre_dist_seg.get(pre[c], pre[c] + subtree[c]);
			if (dist >= largest)
			{
				second = largest;
				largest = dist;
			}
			else if (dist >= second)
			{
				second = dist;
			}
		}

		return largest + second;
	}
};

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:195:16: warning: 'start' may be used uninitialized in this function [-Wmaybe-uninitialized]
  195 |   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 212 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 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 428 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 424 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 212 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 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 428 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 424 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 48 ms 2296 KB Output is correct
20 Correct 38 ms 2400 KB Output is correct
21 Correct 41 ms 2644 KB Output is correct
22 Correct 42 ms 3156 KB Output is correct
23 Correct 82 ms 11032 KB Output is correct
24 Correct 126 ms 13888 KB Output is correct
25 Correct 106 ms 15736 KB Output is correct
26 Correct 109 ms 18072 KB Output is correct

Subtask #3
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 7 ms 340 KB Output is correct
4 Correct 51 ms 524 KB Output is correct
5 Correct 237 ms 896 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 2 ms 596 KB Output is correct
8 Correct 7 ms 468 KB Output is correct
9 Correct 65 ms 596 KB Output is correct
10 Correct 686 ms 832 KB Output is correct
11 Correct 3225 ms 1244 KB Output is correct
12 Correct 18 ms 3244 KB Output is correct
13 Correct 112 ms 3156 KB Output is correct
14 Correct 1070 ms 3156 KB Output is correct
15 Execution timed out 5053 ms 3284 KB Time limit exceeded
16 Halted 0 ms 0 KB -

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 11 ms 2772 KB Output is correct
2 Correct 57 ms 2904 KB Output is correct
3 Correct 255 ms 3448 KB Output is correct
4 Correct 514 ms 4148 KB Output is correct
5 Correct 101 ms 34048 KB Output is correct
6 Correct 199 ms 34204 KB Output is correct
7 Correct 548 ms 34752 KB Output is correct
8 Correct 1085 ms 35680 KB Output is correct
9 Correct 569 ms 200344 KB Output is correct
10 Correct 756 ms 200596 KB Output is correct
11 Correct 1304 ms 201084 KB Output is correct
12 Correct 2064 ms 202108 KB Output is correct
13 Correct 1240 ms 426048 KB Output is correct
14 Correct 1376 ms 426244 KB Output is correct
15 Correct 2098 ms 426924 KB Output is correct
16 Correct 3229 ms 427780 KB Output is correct
17 Execution timed out 5064 ms 427500 KB Time limit exceeded
18 Halted 0 ms 0 KB -

Subtask #5
0 / 24.0

# Verdict Execution time Memory Grader output
1 Execution timed out 5057 ms 325464 KB Time limit exceeded
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 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 212 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 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 428 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 424 KB Output is correct
18 Correct 1 ms 468 KB Output is correct
19 Correct 48 ms 2296 KB Output is correct
20 Correct 38 ms 2400 KB Output is correct
21 Correct 41 ms 2644 KB Output is correct
22 Correct 42 ms 3156 KB Output is correct
23 Correct 82 ms 11032 KB Output is correct
24 Correct 126 ms 13888 KB Output is correct
25 Correct 106 ms 15736 KB Output is correct
26 Correct 109 ms 18072 KB Output is correct
27 Correct 1 ms 212 KB Output is correct
28 Correct 1 ms 212 KB Output is correct
29 Correct 7 ms 340 KB Output is correct
30 Correct 51 ms 524 KB Output is correct
31 Correct 237 ms 896 KB Output is correct
32 Correct 1 ms 212 KB Output is correct
33 Correct 2 ms 596 KB Output is correct
34 Correct 7 ms 468 KB Output is correct
35 Correct 65 ms 596 KB Output is correct
36 Correct 686 ms 832 KB Output is correct
37 Correct 3225 ms 1244 KB Output is correct
38 Correct 18 ms 3244 KB Output is correct
39 Correct 112 ms 3156 KB Output is correct
40 Correct 1070 ms 3156 KB Output is correct
41 Execution timed out 5053 ms 3284 KB Time limit exceeded
42 Halted 0 ms 0 KB -