Submission #261757

#	Time	Username	Problem	Language	Result	Execution time	Memory
261757		ttnhuy313	Bitaro the Brave (JOI19_ho_t1)	C++14	0 / 100	4 ms	5760 KiB

joi2019_ho_t1

#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 (stderr)

joi2019_ho_t1.cpp: In function 'std::vector<std::pair<int, int> > Merge(const std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&)':
joi2019_ho_t1.cpp:16:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
         ~~~~~^~~~~~~~~~~
joi2019_ho_t1.cpp:16:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  while((ind1 < v1.size() || ind2 < v2.size()) && ans.size() < BUCKET_SIZE) {
                             ~~~~~^~~~~~~~~~~
joi2019_ho_t1.cpp:17:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(ind1 < v1.size()) {
      ~~~~~^~~~~~~~~~~
joi2019_ho_t1.cpp:18:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    if(ind2 < v2.size()) {
       ~~~~~^~~~~~~~~~~

• Subtask 1: 0 / 20
• Subtask 2: 0 / 30
• Subtask 3: 0 / 50