Submission #45489

#	Time	Username	Problem	Language	Result	Execution time	Memory
45489		alenam0161	Toy Train (IOI17_train)	C++17	100 / 100	995 ms	10096 KiB

train

#include "train.h"
#include <algorithm>
#include <iostream>
#include <cstdio>
#include <unordered_map>
#include <unordered_set>
#include <queue>

using namespace std;
const int N = 5e3 + 7;
int n, m;

unordered_set<int> R;
vector<int> g[N], g1[N];
vector<int> A;

void rev(vector<bool> &fi){
	for (int i = 0; i < fi.size(); i++)
		fi[i] = !fi[i];
}

void Fw(int w, vector<bool> &fi){
	static queue<int> q;
	for (int i = 0; i < fi.size(); i++)
		if (fi[i])
			q.push(i);

	while (!q.empty()){
		auto it = q.front(); q.pop();
		for (auto to : g1[it]){
			if (fi[to])
				continue;

			if (A[to] == w || all_of(g[to].begin(), g[to].end(), [&](int x){return fi[x] == 1; }))
			{
				fi[to] = true;
				q.push(to);
			}
		}
	}
}

std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
	::n = a.size();
	::A = a;
	::m = u.size();
	vector<int> res;
	
	vector<bool> R;
	for (auto it : r)
		R.push_back(it);

	for (int i = 0; i < m; ++i){
		g[u[i]].push_back(v[i]);
		g1[v[i]].push_back(u[i]);
	}
	while (true){
		static vector<bool> X;
		X = R;
		Fw(1, X);
		rev(X);
		Fw(0, X);

		int cnt = 0;
		for (int i = 0; i < n; i++)
			if (R[i] && X[i])
			{
				cnt++;
				R[i] = false;
			}

		if (cnt == 0){
			auto ans = vector<int>(n, 1);
			for (int i = 0; i < n; i++)
				if (X[i])
					ans[i] = 0;
			return ans;
		}
	}
	return res;
}

Compilation message (stderr)

train.cpp: In function 'void rev(std::vector<bool>&)':
train.cpp:18:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < fi.size(); i++)
                  ~~^~~~~~~~~~~
train.cpp: In function 'void Fw(int, std::vector<bool>&)':
train.cpp:24:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < fi.size(); i++)
                  ~~^~~~~~~~~~~

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