Cod sursa(job #1193556)

Utilizator ZenusTudor Costin Razvan Zenus Data 31 mai 2014 23:29:55
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <cstdio>
#include <vector>
#include <climits>
#include <queue>

using namespace std;

#define NMAX 100003

int D[NMAX];
int N,M,S,i,X,Y;
vector < int > G[NMAX];
queue <int> Q;

void BFS(int nod)
{
    vector < int > :: iterator it;

    Q.push(nod);
    D[nod]=0;

    while (!Q.empty())
    {
        for (it=G[Q.front()].begin();it!=G[Q.front()].end();++it)
        {
            if (D[*it]!=INT_MAX) continue;
            D[*it]=D[Q.front()]+1;
            Q.push(*it);
        }

        Q.pop();
    }
}

int main()
{
freopen("bfs.in","r",stdin);
freopen("bfs.out","w",stdout);

scanf("%d%d%d",&N,&M,&S);

for (i=1;i<=N;++i)
D[i]=INT_MAX;

for (i=1;i<=M;++i)
{
    scanf("%d%d",&X,&Y);
    G[X].push_back(Y);
}

BFS(S);

for (i=1;i<=N;++i)
(D[i]==INT_MAX) ? printf("-1 ") : printf("%d ",D[i]);

return 0;
}