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Submission #739084

# Submission time Handle Problem Language Result Execution time Memory
739084 2023-05-09T23:10:35 Z Qwesz Burza (COCI16_burza) C++14
160 / 160
 54 ms 880 KB 
#include <functional>
#include <iostream>
#include <map>
#include <vector>

using std::cout;
using std::endl;
using std::vector;

int main() {
	int node_num;
	int max_turns;
	std::cin >> node_num >> max_turns;
	vector<vector<int>> neighbors(node_num);
	for (int e = 0; e < node_num - 1; e++) {
		int n1, n2;
		std::cin >> n1 >> n2;
		neighbors[--n1].push_back(--n2);
		neighbors[n2].push_back(n1);
	}

	if (max_turns * max_turns >= node_num) {
		cout << "DA" << endl;
		return 0;
	}

	std::map<int, int> lost;
	vector<vector<int>> cutoff_cover(node_num);
	vector<vector<int>> depth_nodes(max_turns + 1);

	std::function<void(int, int, int)> process_nodes;
	process_nodes = [&](int at, int prev, int depth) {
		depth_nodes[depth].push_back(at);
		if (depth == max_turns) {
			lost[at] = lost.size();
			cutoff_cover[at] = {at};
			return;  // we don't care about anything past this depth
		}
		for (int n : neighbors[at]) {
			if (n != prev) {
				process_nodes(n, at, depth + 1);
				cutoff_cover[at].insert(cutoff_cover[at].end(),
				                        cutoff_cover[n].begin(),
				                        cutoff_cover[n].end());
			}
		}
	};
	process_nodes(0, 0, 0);

	// intervals[n] the interval of leaves we can cover if we cut off node n
	vector<std::pair<int, int>> intervals;
	for (const vector<int> &cc : cutoff_cover) {
		if (cc.empty()) {
			intervals.push_back({-1, -1});
		} else {
			intervals.push_back({lost[cc.front()] + 1, lost[cc.back()] + 1});
		}
	}

	/*
	 * max_cover[ss] contains the max # of leaves we can cover all
	 * the way from the start given that
	 * we only cut off nodes of depths specified in the subsets ss
	 */
	vector<int> max_cover(1 << max_turns);
	max_cover[0] = 0;
	for (int ss = 1; ss < (1 << max_turns); ss++) {
		int &curr = max_cover[ss];
		// go through each possible previous depth
		for (int to_add = 0; to_add < max_turns; to_add++) {
			if ((ss & (1 << to_add)) != 0) {
				int prev = max_cover[ss & ~(1 << to_add)];
				// and all the nodes of said depth
				for (int n : depth_nodes[to_add + 1]) {
					// see if we can cover more nodes than before
					if (intervals[n].first <= prev + 1) {
						curr = std::max(curr, intervals[n].second);
					}
				}
			}
		}

		if (max_cover[ss] == lost.size()) {
			cout << "DA" << endl;
			return 0;
		}
	}

	cout << "NE" << endl;
}

Compilation message

burza.cpp: In function 'int main()':
burza.cpp:83:21: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::map<int, int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   83 |   if (max_cover[ss] == lost.size()) {

Subtask #1
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 340 KB Output is correct
2 Correct 50 ms 868 KB Output is correct
3 Correct 1 ms 304 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 212 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 51 ms 880 KB Output is correct
2 Correct 48 ms 852 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 52 ms 872 KB Output is correct
6 Correct 1 ms 340 KB Output is correct

Subtask #3
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 50 ms 872 KB Output is correct
2 Correct 48 ms 852 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 296 KB Output is correct
5 Correct 1 ms 300 KB Output is correct
6 Correct 0 ms 212 KB Output is correct

Subtask #4
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 468 KB Output is correct
2 Correct 54 ms 872 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 296 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 212 KB Output is correct

Subtask #5
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 46 ms 864 KB Output is correct
2 Correct 53 ms 864 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

Subtask #6
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 53 ms 852 KB Output is correct
2 Correct 52 ms 864 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 300 KB Output is correct

Subtask #7
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 49 ms 852 KB Output is correct
2 Correct 48 ms 852 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 48 ms 864 KB Output is correct
6 Correct 1 ms 300 KB Output is correct

Subtask #8
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 10 ms 468 KB Output is correct
2 Correct 50 ms 852 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 296 KB Output is correct
6 Correct 1 ms 340 KB Output is correct

Subtask #9
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 340 KB Output is correct
2 Correct 49 ms 852 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

Subtask #10
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 620 KB Output is correct
2 Correct 49 ms 864 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 21 ms 628 KB Output is correct
6 Correct 1 ms 212 KB Output is correct