Submission #957964

#	Time	Username	Problem	Language	Result	Execution time	Memory
957964		Soumya1	Park (JOI17_park)	C++17	10 / 100	235 ms	772 KiB

park

#include "park.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = 1405;
vector<int> ad[mxN], edges[mxN];
int added[mxN];
int ask[mxN];
int n;
vector<int> all;
bool bad[mxN];
void get(int u) {
	all.push_back(u);
	for (int v : ad[u]) {
		if (bad[v]) continue;
		get(v);
	}
}
int find_first(vector<int> nodes, int u) {
	for (int i = 0; i < n; i++) ask[i] = 0;
	for (int i : nodes) ask[i] = 1;
	ask[u] = 1;
	if (!Ask(nodes[0], u, ask)) return -1;
	int lo = 0, hi = nodes.size() - 1;
	while (lo < hi) {
		int mid = (lo + hi) >> 1;
		for (int i = 0; i < n; i++) ask[i] = 0;
		for (int i = 0; i <= mid; i++) ask[nodes[i]] = 1;
		ask[u] = 1;
		if (Ask(nodes[0], u, ask)) hi = mid;
		else lo = mid + 1;
	}
	return nodes[lo];
}
void dfs(int u) {
	for (int i = 0; i < n; i++) ask[i] = added[i];
	ask[u] = 1;
	while (!Ask(0, u, ask)) {
		int lo = 0, hi = n - 1;
		while (lo < hi) {
			int mid = (lo + hi) >> 1;
			for (int i = 0; i < n; i++) {
				ask[i] = (added[i] || i <= mid);
			}
			ask[0] = ask[u] = 1;
			if (Ask(0, u, ask)) hi = mid;
			else lo = mid + 1;
		}
		dfs(lo);
		for (int i = 0; i < n; i++) ask[i] = added[i];
		ask[u] = 1;
	}
	for (int i = 0; i < n; i++) bad[i] = false;
	vector<int> roots;
	roots.push_back(0);
	int some = -1;
	for (int i = 0; i < roots.size(); i++) {
		int x = roots[i];
		while (true) {
			all.clear();
			get(x);
			int v = find_first(all, u);
			if (v == -1) break;
			some = v;
			bad[v] = true;
			edges[v].push_back(u);
			for (int childs : ad[v]) roots.push_back(childs);
			if (v == x) break;
		}
	}
	ad[some].push_back(u);
	added[u] = 1;
}
void Detect(int T, int N) {
	n = N;
	added[0] = 1;
	for (int i = 1; i < N; i++) {
		if (!added[i]) {
			dfs(i);
		}
	}
	for (int i = 0; i < n; i++) {
		for (int j : edges[i]) {
			Answer(min(i, j), max(i, j));
		}
	}
}

Compilation message (stderr)

park.cpp: In function 'void dfs(int)':
park.cpp:56:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |  for (int i = 0; i < roots.size(); i++) {
      |                  ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 27
• Subtask 4: 0 / 30
• Subtask 5: 0 / 23