Submission #383476

#	Time	Username	Problem	Language	Result	Execution time	Memory
383476		morato	Bitaro’s Party (JOI18_bitaro)	C++17	7 / 100	2122 ms	418020 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];

pair<int, int> revIn[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 (int i = 0; i < (int) result.size() && (int) caras[a].size() < MAXS; i++) {
		if (!mark[result[i].second]) {
			caras[a].push_back(result[i]);
			mark[result[i].second] = true;
		}
	}
	for (auto x : caras[a]) {
		mark[x.second] = false;
	}
}

void solve(int t, int n) {
	vector<int> lista;
	for (int j = 1; j <= n; j++) {
		best[j] = -1;
		revIn[j].first = revIn[j].second;
		if (!revIn[j].first) lista.push_back(j);
	}
	valid[t] = true;
	best[t] = 0;
	for (int j = 0; j < (int) lista.size(); j++) {
		int cur = lista[j];
		for (int nxt : rev[cur]) {
			revIn[nxt].first--;
			if (!revIn[nxt].first) lista.push_back(nxt);
			if (valid[cur]) {
				valid[nxt] = true;
				best[nxt] = max(best[nxt], best[cur] + 1);
			}
		}
	}
}

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]++;
		revIn[a].first++;
	}
	for (int i = 1; i <= n; i++) {
		revIn[i].second = revIn[i].first;
	}
	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) {
			solve(t, n);
			int ans = -1;
			for (int j = 1; j <= t; j++) {
				valid[j] = false;
				if (!blocked[j]) ans = max(ans, best[j]);
			}
			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:66:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   66 |  scanf("%d %d %d", &n, &m, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
bitaro.cpp:69:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   69 |   scanf("%d %d", &a, &b);
      |   ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:93:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   93 |   scanf("%d %d", &t, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~~
bitaro.cpp:95:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   95 |    scanf("%d", &bosta[j]);
      |    ~~~~~^~~~~~~~~~~~~~~~~

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