oj.uz

Submission #87752

# Submission time Handle Problem Language Result Execution time Memory
87752 2018-12-02T09:30:31 Z JustInCase Bitaro’s Party (JOI18_bitaro) C++17
100 / 100
 1914 ms 412836 KB 
/**
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;
const int32_t INF = 2e9;

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 + 1) {
					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].first + 1, v2[ind2].second });
					}
					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].first + 1, v2[ind2].second });
			}
			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;
	};

	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]);
	}

	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) {
				nodes[i].dp = Merge(nodes[i].dp, x->dp);
			}
		}
	}

	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);

		for(int32_t i = 1; i <= t; i++) {
			if(isForbidden[i]) {
				dp[i] = -INF;
			}
			else {
				dp[i] = 0;
			}

			for(auto &x : nodes[i].v) {
				dp[i] = std::max(dp[i], dp[x->id] + 1);
			}
		}

		return std::max(dp[t], -1);
	}	
};

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:21:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
         ~~~~~^~~~~~~~~~~
bitaro.cpp:21:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
                             ~~~~~^~~~~~~~~~~
bitaro.cpp:22:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(ind1 < v1.size()) {
      ~~~~~^~~~~~~~~~~
bitaro.cpp:23:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(ind2 < v2.size()) {
       ~~~~~^~~~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5752 KB Output is correct
2 Correct 8 ms 5880 KB Output is correct
3 Correct 8 ms 5952 KB Output is correct
4 Correct 8 ms 6028 KB Output is correct
5 Correct 12 ms 6432 KB Output is correct
6 Correct 13 ms 6560 KB Output is correct
7 Correct 13 ms 6604 KB Output is correct
8 Correct 22 ms 9440 KB Output is correct
9 Correct 22 ms 9440 KB Output is correct
10 Correct 20 ms 9568 KB Output is correct
11 Correct 21 ms 9568 KB Output is correct
12 Correct 15 ms 9568 KB Output is correct
13 Correct 19 ms 9568 KB Output is correct
14 Correct 19 ms 9568 KB Output is correct
15 Correct 13 ms 9568 KB Output is correct
16 Correct 19 ms 9568 KB Output is correct
17 Correct 17 ms 9568 KB Output is correct
18 Correct 14 ms 9568 KB Output is correct
19 Correct 18 ms 9568 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5752 KB Output is correct
2 Correct 8 ms 5880 KB Output is correct
3 Correct 8 ms 5952 KB Output is correct
4 Correct 8 ms 6028 KB Output is correct
5 Correct 12 ms 6432 KB Output is correct
6 Correct 13 ms 6560 KB Output is correct
7 Correct 13 ms 6604 KB Output is correct
8 Correct 22 ms 9440 KB Output is correct
9 Correct 22 ms 9440 KB Output is correct
10 Correct 20 ms 9568 KB Output is correct
11 Correct 21 ms 9568 KB Output is correct
12 Correct 15 ms 9568 KB Output is correct
13 Correct 19 ms 9568 KB Output is correct
14 Correct 19 ms 9568 KB Output is correct
15 Correct 13 ms 9568 KB Output is correct
16 Correct 19 ms 9568 KB Output is correct
17 Correct 17 ms 9568 KB Output is correct
18 Correct 14 ms 9568 KB Output is correct
19 Correct 18 ms 9568 KB Output is correct
20 Correct 680 ms 11700 KB Output is correct
21 Correct 606 ms 11700 KB Output is correct
22 Correct 721 ms 11808 KB Output is correct
23 Correct 710 ms 11808 KB Output is correct
24 Correct 1392 ms 253712 KB Output is correct
25 Correct 1480 ms 265284 KB Output is correct
26 Correct 1412 ms 265284 KB Output is correct
27 Correct 1347 ms 412436 KB Output is correct
28 Correct 1365 ms 412668 KB Output is correct
29 Correct 1379 ms 412696 KB Output is correct
30 Correct 1435 ms 412696 KB Output is correct
31 Correct 1587 ms 412696 KB Output is correct
32 Correct 1465 ms 412696 KB Output is correct
33 Correct 1122 ms 412696 KB Output is correct
34 Correct 1092 ms 412696 KB Output is correct
35 Correct 1119 ms 412696 KB Output is correct
36 Correct 1316 ms 412696 KB Output is correct
37 Correct 1318 ms 412696 KB Output is correct
38 Correct 1262 ms 412696 KB Output is correct

Subtask #3
86.0 / 86.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5752 KB Output is correct
2 Correct 8 ms 5880 KB Output is correct
3 Correct 8 ms 5952 KB Output is correct
4 Correct 8 ms 6028 KB Output is correct
5 Correct 12 ms 6432 KB Output is correct
6 Correct 13 ms 6560 KB Output is correct
7 Correct 13 ms 6604 KB Output is correct
8 Correct 22 ms 9440 KB Output is correct
9 Correct 22 ms 9440 KB Output is correct
10 Correct 20 ms 9568 KB Output is correct
11 Correct 21 ms 9568 KB Output is correct
12 Correct 15 ms 9568 KB Output is correct
13 Correct 19 ms 9568 KB Output is correct
14 Correct 19 ms 9568 KB Output is correct
15 Correct 13 ms 9568 KB Output is correct
16 Correct 19 ms 9568 KB Output is correct
17 Correct 17 ms 9568 KB Output is correct
18 Correct 14 ms 9568 KB Output is correct
19 Correct 18 ms 9568 KB Output is correct
20 Correct 680 ms 11700 KB Output is correct
21 Correct 606 ms 11700 KB Output is correct
22 Correct 721 ms 11808 KB Output is correct
23 Correct 710 ms 11808 KB Output is correct
24 Correct 1392 ms 253712 KB Output is correct
25 Correct 1480 ms 265284 KB Output is correct
26 Correct 1412 ms 265284 KB Output is correct
27 Correct 1347 ms 412436 KB Output is correct
28 Correct 1365 ms 412668 KB Output is correct
29 Correct 1379 ms 412696 KB Output is correct
30 Correct 1435 ms 412696 KB Output is correct
31 Correct 1587 ms 412696 KB Output is correct
32 Correct 1465 ms 412696 KB Output is correct
33 Correct 1122 ms 412696 KB Output is correct
34 Correct 1092 ms 412696 KB Output is correct
35 Correct 1119 ms 412696 KB Output is correct
36 Correct 1316 ms 412696 KB Output is correct
37 Correct 1318 ms 412696 KB Output is correct
38 Correct 1262 ms 412696 KB Output is correct
39 Correct 1577 ms 412696 KB Output is correct
40 Correct 1425 ms 412696 KB Output is correct
41 Correct 1527 ms 412696 KB Output is correct
42 Correct 1456 ms 412696 KB Output is correct
43 Correct 1277 ms 412696 KB Output is correct
44 Correct 713 ms 412696 KB Output is correct
45 Correct 691 ms 412696 KB Output is correct
46 Correct 713 ms 412696 KB Output is correct
47 Correct 717 ms 412696 KB Output is correct
48 Correct 731 ms 412696 KB Output is correct
49 Correct 1724 ms 412696 KB Output is correct
50 Correct 1640 ms 412696 KB Output is correct
51 Correct 679 ms 412696 KB Output is correct
52 Correct 622 ms 412696 KB Output is correct
53 Correct 1623 ms 412696 KB Output is correct
54 Correct 1626 ms 412696 KB Output is correct
55 Correct 1496 ms 412696 KB Output is correct
56 Correct 1467 ms 412696 KB Output is correct
57 Correct 720 ms 412696 KB Output is correct
58 Correct 749 ms 412696 KB Output is correct
59 Correct 678 ms 412696 KB Output is correct
60 Correct 688 ms 412696 KB Output is correct
61 Correct 1438 ms 412696 KB Output is correct
62 Correct 1401 ms 412696 KB Output is correct
63 Correct 1404 ms 412696 KB Output is correct
64 Correct 1710 ms 412836 KB Output is correct
65 Correct 1693 ms 412836 KB Output is correct
66 Correct 1700 ms 412836 KB Output is correct
67 Correct 1779 ms 412836 KB Output is correct
68 Correct 1607 ms 412836 KB Output is correct
69 Correct 1578 ms 412836 KB Output is correct
70 Correct 1500 ms 412836 KB Output is correct
71 Correct 1384 ms 412836 KB Output is correct
72 Correct 1317 ms 412836 KB Output is correct
73 Correct 1492 ms 412836 KB Output is correct
74 Correct 1281 ms 412836 KB Output is correct
75 Correct 1249 ms 412836 KB Output is correct
76 Correct 1768 ms 412836 KB Output is correct
77 Correct 1633 ms 412836 KB Output is correct
78 Correct 1391 ms 412836 KB Output is correct
79 Correct 674 ms 412836 KB Output is correct
80 Correct 646 ms 412836 KB Output is correct
81 Correct 654 ms 412836 KB Output is correct
82 Correct 1904 ms 412836 KB Output is correct
83 Correct 1914 ms 412836 KB Output is correct
84 Correct 1763 ms 412836 KB Output is correct
85 Correct 1710 ms 412836 KB Output is correct
86 Correct 1372 ms 412836 KB Output is correct
87 Correct 1523 ms 412836 KB Output is correct
88 Correct 750 ms 412836 KB Output is correct
89 Correct 751 ms 412836 KB Output is correct
90 Correct 723 ms 412836 KB Output is correct
91 Correct 705 ms 412836 KB Output is correct
92 Correct 700 ms 412836 KB Output is correct
93 Correct 714 ms 412836 KB Output is correct
94 Correct 1327 ms 412836 KB Output is correct
95 Correct 1176 ms 412836 KB Output is correct
96 Correct 1238 ms 412836 KB Output is correct
97 Correct 1136 ms 412836 KB Output is correct
98 Correct 1114 ms 412836 KB Output is correct
99 Correct 1120 ms 412836 KB Output is correct
100 Correct 771 ms 412836 KB Output is correct
101 Correct 732 ms 412836 KB Output is correct
102 Correct 736 ms 412836 KB Output is correct
103 Correct 853 ms 412836 KB Output is correct
104 Correct 706 ms 412836 KB Output is correct
105 Correct 731 ms 412836 KB Output is correct
106 Correct 1577 ms 412836 KB Output is correct
107 Correct 1620 ms 412836 KB Output is correct
108 Correct 1550 ms 412836 KB Output is correct
109 Correct 1551 ms 412836 KB Output is correct
110 Correct 1427 ms 412836 KB Output is correct
111 Correct 1317 ms 412836 KB Output is correct
112 Correct 738 ms 412836 KB Output is correct
113 Correct 762 ms 412836 KB Output is correct
114 Correct 721 ms 412836 KB Output is correct
115 Correct 747 ms 412836 KB Output is correct
116 Correct 672 ms 412836 KB Output is correct
117 Correct 716 ms 412836 KB Output is correct
118 Correct 1657 ms 412836 KB Output is correct
119 Correct 1473 ms 412836 KB Output is correct
120 Correct 1424 ms 412836 KB Output is correct
121 Correct 1654 ms 412836 KB Output is correct
122 Correct 1570 ms 412836 KB Output is correct
123 Correct 1512 ms 412836 KB Output is correct
124 Correct 1699 ms 412836 KB Output is correct
125 Correct 1553 ms 412836 KB Output is correct
126 Correct 1475 ms 412836 KB Output is correct