Cod sursa(job #1016088)

Utilizator Cosmin1490Balan Radu Cosmin Cosmin1490 Data 25 octombrie 2013 18:43:12
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.5 kb
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iterator>
#include <assert.h>
using namespace std;

const string file = "bfs";

const string infile = file + ".in";
const string outfile = file + ".out";

const int INF = 0x3f3f3f3f;


int N, M, S;
vector<vector<int> > G;

vector<int> dist;


void BFS(int x)
{
	fill(dist.begin(), dist.end(), INF);
	dist[x] = 0;
	queue<int> q;
	q.push(x);

	while(q.empty() == false)
	{
		int c = q.front();
		q.pop();

		for(vector<int>::iterator itr = G[c].begin();
			itr != G[c].end();
			itr++)
		{
			if(dist[*itr] == INF)
			{
				dist[*itr] = dist[c] + 1;
				q.push(*itr);
			}
		}

	}

}

int main()
{
	fstream fin(infile.c_str(), ios::in);
	fin >> N >> M >> S;
	G.resize(N + 1);
	dist.resize(N + 1);
	for(int i = 0; i < M; i++)
	{
		int x, y;
		fin >> x >> y;
		G[x].push_back(y);
	}
	fin.close();

	BFS(S);


	fstream fout(outfile.c_str(), ios::out);
	for(int i = 1; i <= N; i++)
	{
		fout << (dist[i] == INF ? -1 : dist[i]) << " ";
	}
	fout << "\n";
	fout.close();
}