Cod sursa(job #667370)

Utilizator MultiHackRaul Iulian MultiHack Data 22 ianuarie 2012 22:57:15
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.64 kb
#include<fstream>
#include<vector>
#include<queue>
using namespace std;
int n,m,s;
vector< vector< int > > mat(100001);
vector<int> dist(100001);
int main()
{
	ifstream fin("bfs.in");
	ofstream fout("bfs.out");
	fin>>n>>m>>s;
	for(;m;--m)
	{
		int x,y;
		fin>>x>>y;
		mat[x].push_back(y);
	}
	queue<int> q;
	q.push(s);
	dist[s]=0;
	while(!q.empty())
	{
		int x=q.front();
		for(int i=0;i<mat[x].size();++i)
			if(!dist[mat[x][i]] && mat[x][i]!=s)
			{
				dist[mat[x][i]]=1+dist[x];
				q.push(mat[x][i]);
			}
		q.pop();
	}
	for(int i=1;i<=n;++i)
		if(!dist[i] && i!=s)
			fout<<-1<<" ";
		else
			fout<<dist[i]<<" ";
}