Cod sursa(job #671479)
#include<fstream>
#include<vector>
using namespace std;
//const int maxn=40100;
double long cost[100001],s;
int n,x,y,c[100002],viz[100002],m;
vector <int> A[100001];
ifstream f("bfs.in");
ofstream g("bfs.out");
void citesc()//citim graful
{
int i;
f>>n>>m>>s;
for(i=1;i<=m;i++)
{
f>>x>>y;
A[x].push_back(y);//functia pune arc intre nodul x si nodul y
}
f.close();// inchidem primul fisier
}
void bfs(int k)
{
int li,ls,nod,nr_vecini,i;//li reprezinta limita superioara. ls reprezinta limita interioara
li=1;
ls=1;
c[li]=k;
viz[k]=1;
while(li<=ls)// cat timp li<= ls executa comanda
{
nod=c[li];
nr_vecini=A[nod].size();// functia A[nod].size returneaza numarul vecinilor nodului respectiv
for(i=0;i<nr_vecini;i++)
if(viz[A[nod][i]]==0)
{
ls++;
c[ls]=A[nod][i];
viz[A[nod][i]]=1;
cost[A[nod][i]]=cost[nod]+1;
}
}
li++;
}
int main()
{
int i;
citesc();
bfs(s);
for(i=1;i<=n;i++)
if(cost[i]!=0 || i==s)
g<<cost[i]<<" ";
else
g<<-1;
return 0;
}