Cod sursa(job #1113937)

Utilizator cristi103tiron cristian cristi103 Data 21 februarie 2014 08:16:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.63 kb
#include <fstream>
#include <vector>
#include <queue>
#define nmax 1000005
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
vector<int> a[nmax];
int n,m,s,d[nmax],x,y;
bool viz[nmax];
void citire()
{
f>>n>>m>>s;
for(int i=1;i<=m;i++)
{
f>>x>>y;
a[x].push_back(y);
}
}
void bfs (int x)
{
viz[x]=1;
queue<int>q;
q.push(x);
while(!q.empty())
{
x=q.front();
q.pop();
for(int i=0;i<a[x].size();i++)
{
int p=a[x][i];
if(!viz[p])
{
d[p]=d[x]+1;
q.push(p);
viz[p]=1;
}
}
}
}
int main()
{
citire();
bfs(s);
for(int i=1;i<=n;i++)
{
if(viz[i])
g<<d[i];
else
g<<"-1";
g<<" ";
}
return 0;
}