Submission #383477

#	Time	Username	Problem	Language	Result	Execution time	Memory
383477		morato	Bitaro’s Party (JOI18_bitaro)	C++17	0 / 100	9 ms	8044 KiB

bitaro

#include <bits/stdc++.h>

using namespace std;

const int MAXN = 1e5 + 5;
const int MAXS = 320;

vector<int> adj[MAXN], rev[MAXN];

vector<pair<int, int>> caras[MAXN];

int in[MAXN], bosta[MAXN], best[MAXN], dp[MAXN];

bool mark[MAXN], blocked[MAXN], valid[MAXN];

void merge(int a, int b) {
	vector<pair<int, int>> result;
	int j = 0;
	for (int i = 0; i < (int) caras[a].size(); i++) {
		for (; j < (int) caras[b].size() && caras[b][j].first + 1 > caras[a][i].first; j++) {
			result.push_back({caras[b][j].first + 1, caras[b][j].second});
		}
		result.push_back(caras[a][i]);
	}
	for (; j < (int) caras[b].size(); j++) {
		result.push_back({caras[b][j].first + 1, caras[b][j].second});
	}
	caras[a].clear();
	for (auto x : result) {
		if (!mark[x.second] && (int) caras[a].size() < MAXS + 1) {
			caras[a].push_back(x);
			mark[x.second] = true;
		}
	}
	for (auto x : caras[a]) {
		mark[x.second] = false;
	}
}

int solve(int v) {
	int ans = 0;
	for (int u : rev[v]) {
		if (dp[u] == -1) {
			ans = max(ans, solve(u) + 1);
		} else {
			ans = max(ans, dp[u] + 1);
		}
	}
	return dp[v] = ans;
}

int main(){
	int n, m, q;
	scanf("%d %d %d", &n, &m, &q);
	for (int i = 0; i < m; i++) {
		int a, b;
		scanf("%d %d", &a, &b);
		adj[a].push_back(b);
		rev[b].push_back(a);
		in[b]++;
	}
	vector<int> lista;
	for (int i = 1; i <= n; i++) {
		caras[i].push_back({0, i});
		if (!in[i]) lista.push_back(i);
	}
	for (int i = 0; i < (int) lista.size(); i++) {
		int cur = lista[i];
		for (int nxt : adj[cur]) {
			in[nxt]--;
			if (!in[nxt]) lista.push_back(nxt);
			merge(nxt, cur);
		}
	}
	for (int i = 0; i < q; i++) {
		int t, y;
		scanf("%d %d", &t, &y);
		for (int j = 0; j < y; j++) {
			scanf("%d", &bosta[j]);
			blocked[bosta[j]] = true;
		}
		if (y > MAXS) {
			for (int j = 1; j <= n; j++) {
				dp[j] = -1;
			}
			int ans = (solve(t) == 0 ? blocked[t] ? -1 : 0 : dp[t]);
			printf("%d\n", ans);
		} else {
			int ans = -1;
			for (auto x : caras[t]) {
				if (!blocked[x.second]) {
					ans = x.first;
					break;
				}
			}
			printf("%d\n", ans);
		}
		for (int j = 0; j < y; j++) {
			blocked[bosta[j]] = false;
		}
	}
	return 0; 
}

Compilation message (stderr)

bitaro.cpp: In function 'int main()':
bitaro.cpp:54:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   54 |  scanf("%d %d %d", &n, &m, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:57:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   57 |   scanf("%d %d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:77:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   77 |   scanf("%d %d", &t, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:79:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   79 |    scanf("%d", &bosta[j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~

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