답안 #87729 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
87729	2018-12-02T08:31:53 Z	JustInCase	Bitaro’s Party (JOI18_bitaro)	C++17	14 / 100	2000 ms	31584 KB

bitaro

/**
Solution:
	Idea: We can precompute for each node the sqrt(n) furthest nodes with a simple dp. Then for each query
if the number of forbidden nodes is less than sqrt(n) then for sure the answer will be among the precomputed
otherwise we can simply solve it with a brutefore since the queries of this type will be less than sqrt(n).
*/
#include <bits/stdc++.h>

const int32_t MAX_N = 1e5;
const int32_t BUCKET_SIZE = 10;

bool isForbidden[MAX_N + 5];

class Graph {
private:
	struct Node {
		int32_t id;
		std::vector< std::pair< int32_t, int32_t > > dp;
		std::vector< Node* > v, rev;
	};

	int32_t cntNodes;
	Node nodes[MAX_N + 5];
	
public:
	void Init(int32_t _cntNodes) {
		cntNodes = _cntNodes;

		for(int32_t i = 1; i <= cntNodes; i++) {
			nodes[i].id = i;
		}
	}

	void AddEdge(int32_t from, int32_t to) {
		nodes[from].v.push_back(&nodes[to]);
		nodes[to].rev.push_back(&nodes[from]);
	}

	void Precompute() {
		for(int32_t i = 1; i <= cntNodes; i++) {
			std::vector< std::pair< int32_t, int32_t > > dists;
			
			dists.push_back({ 0, i });
			for(auto &x : nodes[i].v) {
				for(auto &y : x->dp) {
					dists.push_back({ y.first + 1, y.second });
				}
			}

			std::sort(dists.begin(), dists.end());
			
			for(int32_t j = dists.size() - 1; j >= 0; j--) {
				if(nodes[i].dp.size() == 0 || nodes[i].dp.back().second != dists[j].second) {
					nodes[i].dp.push_back(dists[j]);

					if(nodes[i].dp.size() == BUCKET_SIZE) {
						break;
					}
				}
			}
		}
	}

	int32_t SolveSmallK(int32_t t) {
		for(auto &x : nodes[t].dp) {
			if(!isForbidden[x.second]) {
				return x.first;
			}
		}

		return -1;
	}

	int32_t SolveBigK(int32_t t) {
		std::vector< int32_t > dp(t + 1, 0);

		int32_t ans = (isForbidden[t] ? -1 : 0);
		for(int32_t i = t - 1; i >= 1; i--) {
			bool isChanged = false;
			for(auto &x : nodes[i].rev) {
				if(x->id <= t && (x->id == t || dp[x->id] != 0)) {
					dp[i] = std::max(dp[i], dp[x->id] + 1);
					isChanged = true;
				}
			}
			
			if(isChanged && !isForbidden[i]) {
				ans = std::max(ans, dp[i]);
			}
		}

		return ans;
	}	
};

Graph g;

int main() {
	std::ios_base::sync_with_stdio(false);
	std::cin.tie(nullptr);

	int32_t n, m, q;
	std::cin >> n >> m >> q;

	g.Init(n);
	
	for(int32_t i = 0; i < m; i++) {
		int32_t u, v;
		std::cin >> u >> v;

		g.AddEdge(v, u);
	}
	
	g.Precompute();

	for(int32_t i = 0; i < q; i++) {
		int32_t t, k;
		std::cin >> t >> k;
	
		std::vector< int32_t > c(k);
		for(int32_t j = 0; j < k; j++) {
			std::cin >> c[j];

			isForbidden[c[j]] = true;
		}

		if(k >= BUCKET_SIZE) {
			std::cout << g.SolveBigK(t) << '\n';
		}
		else {
			std::cout << g.SolveSmallK(t) << '\n';
		}

		for(int32_t j = 0; j < k; j++) {
			isForbidden[c[j]] = false;
		}
	}
}

Subtask #1
7.0 / 7.0

#	결과	실행 시간	메모리	Grader output
1	Correct	10 ms	8184 KB	Output is correct
2	Correct	10 ms	8188 KB	Output is correct
3	Correct	10 ms	8232 KB	Output is correct
4	Correct	9 ms	8232 KB	Output is correct
5	Correct	13 ms	8588 KB	Output is correct
6	Correct	11 ms	8588 KB	Output is correct
7	Correct	10 ms	8588 KB	Output is correct
8	Correct	12 ms	8608 KB	Output is correct
9	Correct	13 ms	8640 KB	Output is correct
10	Correct	12 ms	8640 KB	Output is correct
11	Correct	11 ms	8768 KB	Output is correct
12	Correct	13 ms	8768 KB	Output is correct
13	Correct	13 ms	8768 KB	Output is correct
14	Correct	12 ms	8768 KB	Output is correct
15	Correct	14 ms	8768 KB	Output is correct
16	Correct	14 ms	8768 KB	Output is correct
17	Correct	12 ms	8768 KB	Output is correct
18	Correct	11 ms	8768 KB	Output is correct
19	Correct	13 ms	8768 KB	Output is correct

Subtask #2
7.0 / 7.0

#	결과	실행 시간	메모리	Grader output
1	Correct	10 ms	8184 KB	Output is correct
2	Correct	10 ms	8188 KB	Output is correct
3	Correct	10 ms	8232 KB	Output is correct
4	Correct	9 ms	8232 KB	Output is correct
5	Correct	13 ms	8588 KB	Output is correct
6	Correct	11 ms	8588 KB	Output is correct
7	Correct	10 ms	8588 KB	Output is correct
8	Correct	12 ms	8608 KB	Output is correct
9	Correct	13 ms	8640 KB	Output is correct
10	Correct	12 ms	8640 KB	Output is correct
11	Correct	11 ms	8768 KB	Output is correct
12	Correct	13 ms	8768 KB	Output is correct
13	Correct	13 ms	8768 KB	Output is correct
14	Correct	12 ms	8768 KB	Output is correct
15	Correct	14 ms	8768 KB	Output is correct
16	Correct	14 ms	8768 KB	Output is correct
17	Correct	12 ms	8768 KB	Output is correct
18	Correct	11 ms	8768 KB	Output is correct
19	Correct	13 ms	8768 KB	Output is correct
20	Correct	210 ms	13280 KB	Output is correct
21	Correct	206 ms	13308 KB	Output is correct
22	Correct	208 ms	13308 KB	Output is correct
23	Correct	202 ms	13564 KB	Output is correct
24	Correct	353 ms	27568 KB	Output is correct
25	Correct	332 ms	27568 KB	Output is correct
26	Correct	453 ms	27568 KB	Output is correct
27	Correct	442 ms	31556 KB	Output is correct
28	Correct	405 ms	31556 KB	Output is correct
29	Correct	340 ms	31584 KB	Output is correct
30	Correct	328 ms	31584 KB	Output is correct
31	Correct	327 ms	31584 KB	Output is correct
32	Correct	327 ms	31584 KB	Output is correct
33	Correct	280 ms	31584 KB	Output is correct
34	Correct	297 ms	31584 KB	Output is correct
35	Correct	297 ms	31584 KB	Output is correct
36	Correct	296 ms	31584 KB	Output is correct
37	Correct	316 ms	31584 KB	Output is correct
38	Correct	326 ms	31584 KB	Output is correct

Subtask #3
0 / 86.0

#	결과	실행 시간	메모리	Grader output
1	Correct	10 ms	8184 KB	Output is correct
2	Correct	10 ms	8188 KB	Output is correct
3	Correct	10 ms	8232 KB	Output is correct
4	Correct	9 ms	8232 KB	Output is correct
5	Correct	13 ms	8588 KB	Output is correct
6	Correct	11 ms	8588 KB	Output is correct
7	Correct	10 ms	8588 KB	Output is correct
8	Correct	12 ms	8608 KB	Output is correct
9	Correct	13 ms	8640 KB	Output is correct
10	Correct	12 ms	8640 KB	Output is correct
11	Correct	11 ms	8768 KB	Output is correct
12	Correct	13 ms	8768 KB	Output is correct
13	Correct	13 ms	8768 KB	Output is correct
14	Correct	12 ms	8768 KB	Output is correct
15	Correct	14 ms	8768 KB	Output is correct
16	Correct	14 ms	8768 KB	Output is correct
17	Correct	12 ms	8768 KB	Output is correct
18	Correct	11 ms	8768 KB	Output is correct
19	Correct	13 ms	8768 KB	Output is correct
20	Correct	210 ms	13280 KB	Output is correct
21	Correct	206 ms	13308 KB	Output is correct
22	Correct	208 ms	13308 KB	Output is correct
23	Correct	202 ms	13564 KB	Output is correct
24	Correct	353 ms	27568 KB	Output is correct
25	Correct	332 ms	27568 KB	Output is correct
26	Correct	453 ms	27568 KB	Output is correct
27	Correct	442 ms	31556 KB	Output is correct
28	Correct	405 ms	31556 KB	Output is correct
29	Correct	340 ms	31584 KB	Output is correct
30	Correct	328 ms	31584 KB	Output is correct
31	Correct	327 ms	31584 KB	Output is correct
32	Correct	327 ms	31584 KB	Output is correct
33	Correct	280 ms	31584 KB	Output is correct
34	Correct	297 ms	31584 KB	Output is correct
35	Correct	297 ms	31584 KB	Output is correct
36	Correct	296 ms	31584 KB	Output is correct
37	Correct	316 ms	31584 KB	Output is correct
38	Correct	326 ms	31584 KB	Output is correct
39	Correct	415 ms	31584 KB	Output is correct
40	Execution timed out	2007 ms	31584 KB	Time limit exceeded
41	Halted	0 ms	0 KB	-

답안 #87729

Compilation message

Subtask #1 7.0 / 7.0

Subtask #2 7.0 / 7.0

Subtask #3 0 / 86.0

Subtask #1
7.0 / 7.0

Subtask #2
7.0 / 7.0

Subtask #3
0 / 86.0