Cod sursa(job #368507)

Utilizator mihaimoldovanMihai Moldovan mihaimoldovan Data 25 noiembrie 2009 08:45:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.85 kb
#include<fstream>
#include<iostream>
using namespace std;
#define max 100001
int n,*a[max],d[max],s;
void read()
{
	int m,i,j;
	ifstream fin("bfs.in");
	fin>>n>>m>>s;
	int *grad=new int [n+1];
	for(int i=1;i<=n;i++)
		grad[i]=0;
	for(;m;m--)
	{
		fin>>i>>j;
		grad[i]++;
	}
	fin.close();
	fin.open("bfs.in");
	fin>>n>>m>>s;
	for(int i=1;i<=n;i++)
		{
			a[i]=new int [grad[i]+1];
			a[i][0]=0;
			d[i]=-1;
		}
	delete [] grad;
	for(;m;m--)
	{
		fin>>i>>j;
		a[i][++a[i][0]]=j;
	}
}
void bfs()
{
	int *coada=new int [n+1],st=1,dr=1,i,k;
	coada[st]=s;
	d[s]=0;
	while(st<=dr)
	{
		k=coada[st++];
		for(i=1;i<=a[k][0];i++)
		{
			if(d[a[k][i]]==-1)
			{
				coada[++dr]=a[k][i];
				d[a[k][i]]=d[k]+1;
			}
		}
			
	}
}
void write()
{
	ofstream fout("bfs.out");
	for(int i=1;i<=n;i++)
		fout<<d[i]<<" ";
	fout.close();
}
int main()
{
	read();
	bfs();
	write();
	return 0;
}