Submission #479690

#	Time	Username	Problem	Language	Result	Execution time	Memory
479690		MilosMilutinovic	Bitaro’s Party (JOI18_bitaro)	C++14	7 / 100	2074 ms	15756 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;
const int M = 2000;

vector<int> g[N], rg[N];
vector<pair<int, int>> all[N];
bool can[N];
int qId[N], dp[N];

void dfs1(int u) {
	for (int v : rg[u]) {
		dp[v] = max(dp[v], dp[u] + 1);
	}
	for (int v : rg[u]) {
		dfs1(v);
	}
}

int main()
{
	int n, m, q;
	scanf("%d%d%d", &n, &m, &q);
	for (int i = 1; i <= m; i++) {
		int u, v;
		scanf("%d%d", &u, &v);
		--u; --v;
		g[u].push_back(v);
		rg[v].push_back(u);
	}
	for (int u = 0; u < n; u++) {
		vector<pair<int, int>> Edges;
		Edges.push_back({0, u});
		for (int v : rg[u]) {
			for (auto his : all[v]) {
				Edges.push_back({his.first + 1, his.second});
			}
		}
		sort(Edges.begin(), Edges.end(), [&](pair<int, int> X, pair<int, int> Y) {
			if (X.second != Y.second) {
				return X.second < Y.second;
			}
			return X.first < Y.first;
		});
		vector<pair<int, int>> edg;
		for (int i = 0; i < Edges.size(); i++) {
			if (i + 1 == Edges.size() || Edges[i].second != Edges[i + 1].second) {
				edg.push_back(Edges[i]);
			}
		}
		sort(edg.rbegin(), edg.rend());
		for (int i = 0; i < edg.size(); i++) {
			if (all[u].size() + 1 <= M) {
				all[u].push_back(edg[i]);
			}
		}
	}
	/*for (int i = 0; i < n; i++) {
		printf("node %d: ", i);
		for (auto my : all[i]) {
			printf("%d ", my.first);
		}
		printf("\n");
	}*/
	for (int i = 0; i < n; i++) can[i] = true;
	for (int i = 0; i < n; i++) sort(g[i].begin(), g[i].end());
	for (int i = 0; i < n; i++) sort(rg[i].rbegin(), rg[i].rend());
	while (q--) {
		int st, qSz;
		scanf("%d%d", &st, &qSz);
		--st;
		for (int i = 0; i < qSz; i++) {
			scanf("%d", &qId[i]);
			--qId[i];
			can[qId[i]] = false;
		}

		if (qSz >= M) {
			for (int i = 0; i < n; i++) dp[i] = 0;
			dfs1(st);
			int ans = -1;
			for (int i = 0; i < n; i++) {
				if (can[i]) ans = max(ans, dp[i]);
				else can[i] = true;
			}
			printf("%d\n", ans);
		} else {
			int ans = -1;
			for (auto d : all[st]) {
				if (can[d.second]) {
					ans = max(ans, d.first);
				}
			}
			for (int i = 0; i < qSz; i++) can[qId[i]] = true;
			printf("%d\n", ans);
		}
	}
	return 0;
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:48:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   48 |   for (int i = 0; i < Edges.size(); i++) {
      |                   ~~^~~~~~~~~~~~~~
bitaro.cpp:49:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |    if (i + 1 == Edges.size() || Edges[i].second != Edges[i + 1].second) {
      |        ~~~~~~^~~~~~~~~~~~~~~
bitaro.cpp:54:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   54 |   for (int i = 0; i < edg.size(); i++) {
      |                   ~~^~~~~~~~~~~~
bitaro.cpp:25:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |  scanf("%d%d%d", &n, &m, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:28:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   28 |   scanf("%d%d", &u, &v);
      |   ~~~~~^~~~~~~~~~~~~~~~
bitaro.cpp:72:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |   scanf("%d%d", &st, &qSz);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~
bitaro.cpp:75:9: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   75 |    scanf("%d", &qId[i]);
      |    ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 0 / 7
• Subtask 3: 0 / 86