답안 #87744 :: oj.uz

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
87744	2018-12-02T09:11:25 Z	JustInCase	Bitaro’s Party (JOI18_bitaro)	C++17	14 / 100	2000 ms	420308 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 = 300;

bool isInVector[MAX_N + 5];
bool isForbidden[MAX_N + 5];

std::vector< std::pair< int32_t, int32_t > > Merge(const std::vector< std::pair< int32_t, int32_t> > &v1, 
		const std::vector< std::pair< int32_t, int32_t > > &v2) {
	std::vector< std::pair< int32_t, int32_t > > ans;

	int32_t ind1 = 0, ind2 = 0;
	while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
		if(ind1 < v1.size()) {
			if(ind2 < v2.size()) {
				if(v1[ind1].first >= v2[ind2].first) {
					if(!isInVector[v1[ind1].second]) {
						isInVector[v1[ind1].second] = true;
						ans.push_back(v1[ind1]);
					}
					ind1++;
				}
				else {
					if(!isInVector[v2[ind2].second]) {
						isInVector[v2[ind2].second] = true;
						ans.push_back(v2[ind2]);
					}
					ind2++;
				}
			}
			else {
				if(!isInVector[v1[ind1].second]) {
					isInVector[v1[ind1].second] = true;
					ans.push_back(v1[ind1]);
				}
				ind1++;
			}
		}
		else {
			if(!isInVector[v2[ind2].second]) {
				isInVector[v2[ind2].second] = true;
				ans.push_back(v2[ind2]);
			}
			ind2++;
		}
	}

	for(auto &x : ans) {
		isInVector[x.second] = false;
	}

	return ans;
}

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;
			
			nodes[i].dp.push_back({ 0, i });
			for(auto &x : nodes[i].v) {
				auto aux = x->dp;
				for(auto &y : aux) {
					y.first++;
				}
				nodes[i].dp = Merge(nodes[i].dp, aux);
			}
		}
	}

	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;
		}
	}
}

Compilation message

bitaro.cpp: In function 'std::vector<std::pair<int, int> > Merge(const std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&)':
bitaro.cpp:20:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
         ~~~~~^~~~~~~~~~~
bitaro.cpp:20:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
                             ~~~~~^~~~~~~~~~~
bitaro.cpp:21:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(ind1 < v1.size()) {
      ~~~~~^~~~~~~~~~~
bitaro.cpp:22:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(ind2 < v2.size()) {
       ~~~~~^~~~~~~~~~~

Subtask #1
7.0 / 7.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	8184 KB	Output is correct
2	Correct	10 ms	8252 KB	Output is correct
3	Correct	11 ms	8476 KB	Output is correct
4	Correct	10 ms	8476 KB	Output is correct
5	Correct	14 ms	8756 KB	Output is correct
6	Correct	15 ms	8756 KB	Output is correct
7	Correct	14 ms	8796 KB	Output is correct
8	Correct	25 ms	11768 KB	Output is correct
9	Correct	24 ms	11808 KB	Output is correct
10	Correct	24 ms	11936 KB	Output is correct
11	Correct	23 ms	11936 KB	Output is correct
12	Correct	18 ms	11936 KB	Output is correct
13	Correct	24 ms	11936 KB	Output is correct
14	Correct	20 ms	11936 KB	Output is correct
15	Correct	17 ms	11936 KB	Output is correct
16	Correct	20 ms	11936 KB	Output is correct
17	Correct	20 ms	11936 KB	Output is correct
18	Correct	18 ms	11936 KB	Output is correct
19	Correct	21 ms	11936 KB	Output is correct

Subtask #2
7.0 / 7.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	8184 KB	Output is correct
2	Correct	10 ms	8252 KB	Output is correct
3	Correct	11 ms	8476 KB	Output is correct
4	Correct	10 ms	8476 KB	Output is correct
5	Correct	14 ms	8756 KB	Output is correct
6	Correct	15 ms	8756 KB	Output is correct
7	Correct	14 ms	8796 KB	Output is correct
8	Correct	25 ms	11768 KB	Output is correct
9	Correct	24 ms	11808 KB	Output is correct
10	Correct	24 ms	11936 KB	Output is correct
11	Correct	23 ms	11936 KB	Output is correct
12	Correct	18 ms	11936 KB	Output is correct
13	Correct	24 ms	11936 KB	Output is correct
14	Correct	20 ms	11936 KB	Output is correct
15	Correct	17 ms	11936 KB	Output is correct
16	Correct	20 ms	11936 KB	Output is correct
17	Correct	20 ms	11936 KB	Output is correct
18	Correct	18 ms	11936 KB	Output is correct
19	Correct	21 ms	11936 KB	Output is correct
20	Correct	808 ms	16272 KB	Output is correct
21	Correct	753 ms	16272 KB	Output is correct
22	Correct	845 ms	16272 KB	Output is correct
23	Correct	870 ms	16272 KB	Output is correct
24	Correct	1408 ms	260188 KB	Output is correct
25	Correct	1351 ms	271788 KB	Output is correct
26	Correct	1427 ms	271788 KB	Output is correct
27	Correct	1393 ms	419340 KB	Output is correct
28	Correct	1545 ms	419416 KB	Output is correct
29	Correct	1539 ms	419656 KB	Output is correct
30	Correct	1446 ms	419656 KB	Output is correct
31	Correct	1436 ms	419656 KB	Output is correct
32	Correct	1422 ms	419656 KB	Output is correct
33	Correct	1178 ms	419656 KB	Output is correct
34	Correct	1065 ms	419656 KB	Output is correct
35	Correct	1106 ms	419656 KB	Output is correct
36	Correct	1282 ms	419656 KB	Output is correct
37	Correct	1301 ms	419656 KB	Output is correct
38	Correct	1277 ms	419656 KB	Output is correct

Subtask #3
0 / 86.0

#	결과	실행 시간	메모리	Grader output
1	Correct	11 ms	8184 KB	Output is correct
2	Correct	10 ms	8252 KB	Output is correct
3	Correct	11 ms	8476 KB	Output is correct
4	Correct	10 ms	8476 KB	Output is correct
5	Correct	14 ms	8756 KB	Output is correct
6	Correct	15 ms	8756 KB	Output is correct
7	Correct	14 ms	8796 KB	Output is correct
8	Correct	25 ms	11768 KB	Output is correct
9	Correct	24 ms	11808 KB	Output is correct
10	Correct	24 ms	11936 KB	Output is correct
11	Correct	23 ms	11936 KB	Output is correct
12	Correct	18 ms	11936 KB	Output is correct
13	Correct	24 ms	11936 KB	Output is correct
14	Correct	20 ms	11936 KB	Output is correct
15	Correct	17 ms	11936 KB	Output is correct
16	Correct	20 ms	11936 KB	Output is correct
17	Correct	20 ms	11936 KB	Output is correct
18	Correct	18 ms	11936 KB	Output is correct
19	Correct	21 ms	11936 KB	Output is correct
20	Correct	808 ms	16272 KB	Output is correct
21	Correct	753 ms	16272 KB	Output is correct
22	Correct	845 ms	16272 KB	Output is correct
23	Correct	870 ms	16272 KB	Output is correct
24	Correct	1408 ms	260188 KB	Output is correct
25	Correct	1351 ms	271788 KB	Output is correct
26	Correct	1427 ms	271788 KB	Output is correct
27	Correct	1393 ms	419340 KB	Output is correct
28	Correct	1545 ms	419416 KB	Output is correct
29	Correct	1539 ms	419656 KB	Output is correct
30	Correct	1446 ms	419656 KB	Output is correct
31	Correct	1436 ms	419656 KB	Output is correct
32	Correct	1422 ms	419656 KB	Output is correct
33	Correct	1178 ms	419656 KB	Output is correct
34	Correct	1065 ms	419656 KB	Output is correct
35	Correct	1106 ms	419656 KB	Output is correct
36	Correct	1282 ms	419656 KB	Output is correct
37	Correct	1301 ms	419656 KB	Output is correct
38	Correct	1277 ms	419656 KB	Output is correct
39	Correct	1616 ms	419656 KB	Output is correct
40	Correct	1531 ms	419656 KB	Output is correct
41	Correct	1595 ms	419656 KB	Output is correct
42	Correct	1753 ms	419656 KB	Output is correct
43	Correct	1400 ms	419656 KB	Output is correct
44	Correct	849 ms	419656 KB	Output is correct
45	Correct	807 ms	419656 KB	Output is correct
46	Correct	818 ms	419656 KB	Output is correct
47	Correct	876 ms	419656 KB	Output is correct
48	Correct	858 ms	419656 KB	Output is correct
49	Correct	1747 ms	420160 KB	Output is correct
50	Correct	1650 ms	420160 KB	Output is correct
51	Correct	772 ms	420160 KB	Output is correct
52	Correct	746 ms	420160 KB	Output is correct
53	Correct	1575 ms	420160 KB	Output is correct
54	Correct	1576 ms	420160 KB	Output is correct
55	Correct	1536 ms	420160 KB	Output is correct
56	Correct	1471 ms	420160 KB	Output is correct
57	Correct	828 ms	420160 KB	Output is correct
58	Correct	891 ms	420160 KB	Output is correct
59	Correct	828 ms	420160 KB	Output is correct
60	Correct	851 ms	420160 KB	Output is correct
61	Correct	1795 ms	420160 KB	Output is correct
62	Correct	1613 ms	420160 KB	Output is correct
63	Correct	1552 ms	420160 KB	Output is correct
64	Execution timed out	2086 ms	420308 KB	Time limit exceeded
65	Halted	0 ms	0 KB	-

답안 #87744

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