Submission #547473

#	Time	Username	Problem	Language	Result	Execution time	Memory
547473		blue	Toy Train (IOI17_train)	C++17	12 / 100	9 ms	1748 KiB

train

#include "train.h"
#include <vector>
#include <queue>
#include <algorithm>
#include <iostream>
using namespace std;

using vi = vector<int>;
#define sz(x) int(x.size())


 //a = owner, r = charging
vi who_wins(vi a, vi r, vi U, vi V) 
{
	int n = sz(a);
	int m = sz(U);

	vi edge[n];
	vi revedge[n];
	for(int j = 0; j < m; j++)
	{
		edge[U[j]].push_back(V[j]);
		revedge[V[j]].push_back(U[j]);
	}



	vi good(n, 0);
	vi pushed(n, 0);

	queue<int> tbv;

	for(int i = 0; i < n; i++)
	{
		if(r[i])
		{
			good[i] = 1;
			tbv.push(i);
			pushed[i] = 1;
		}
	}

	vi deg(n, 0);
	for(int j = 0; j < m; j++)
		deg[U[j]]++;
	// cerr << "done\n";

	while(!tbv.empty())
	{
		int u = tbv.front();
		tbv.pop();
		// cerr << "u = " << u << '\n';

		for(int v : revedge[u])
		{
			if(pushed[v]) continue;

			if(a[v] == 1)
			{
				pushed[v] = 1;
				tbv.push(v);
				good[v] = 1;
			}
			else
			{
				deg[v]--;
				if(deg[v] == 0)
				{
					pushed[v] = 1;
					tbv.push(v);
					good[v] = 1;
				}
			}
		}
	}

	int cs = 0;
	while(!r[cs])
		cs++;

	bool works;
	if(a[cs] == 1)
	{
		works = 0;
		for(int v : edge[cs])
			if(good[v])
				works = 1;
	}
	else
	{
		works = 1;
		for(int v : edge[cs])
			if(!good[v])
				works = 0;
	}

	if(!works) good = vi(n, 0);

	return good;	
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 12 / 12
• Subtask 6: 0 / 51