Submission #1039395

#	Time	Username	Problem	Language	Result	Execution time	Memory
1039395		Soumya1	Toy Train (IOI17_train)	C++17	100 / 100	394 ms	3672 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = 5005;
set<int> ad[mxN], rev[mxN];
vector<int> who_wins(vector<int> a, vector<int> r, vector<int> u, vector<int> v) {
	int n = a.size();
	for (int i = 0; i < u.size(); i++) {
		ad[u[i]].insert(v[i]);
		rev[v[i]].insert(u[i]);
	}
	auto get = [&](vector<int> s, int type) {
		vector<int> out(n), vis(n);
		for (int i : s) vis[i] = true;
		for (int i = 0; i < s.size(); i++) {
			int u = s[i];
			for (int v : rev[u]) {
				out[v]++;
				if (!vis[v] && out[v] >= (a[v] == type ? 1 : ad[v].size())) {
					s.push_back(v);
					vis[v] = true;
				}
			}
		}
		return s;
	};
	vector<bool> removed(n);
	while (true) {
		vector<int> on;
		for (int i = 0; i < n; i++) {
			if (r[i] && !removed[i]) on.push_back(i);
		}
		vector<bool> can(n);
		on = get(on, 1);
		for (int i : on) can[i] = true;
		vector<int> bad;
		for (int i = 0; i < n; i++) {
			if (!removed[i] && !can[i]) bad.push_back(i);
		}
		bad = get(bad, 0);
		if (bad.empty()) break;
		for (int i : bad) {
			removed[i] = true;
			for (int j : ad[i]) rev[j].erase(i);
			for (int j : rev[i]) ad[j].erase(i);
			rev[i].clear();
			ad[i].clear();
		}
	}
	vector<int> ans(n);
	for (int i = 0; i < n; i++) ans[i] = !removed[i];
	return ans;
}

Compilation message (stderr)

train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:8:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |  for (int i = 0; i < u.size(); i++) {
      |                  ~~^~~~~~~~~~
train.cpp: In lambda function:
train.cpp:15:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |   for (int i = 0; i < s.size(); i++) {
      |                   ~~^~~~~~~~~~
train.cpp:19:27: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'long unsigned int' [-Wsign-compare]
   19 |     if (!vis[v] && out[v] >= (a[v] == type ? 1 : ad[v].size())) {

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 11 / 11
• Subtask 4: 11 / 11
• Subtask 5: 12 / 12
• Subtask 6: 51 / 51