Cod sursa(job #1848847)

Utilizator leraValeria lera Data 16 ianuarie 2017 18:58:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector<int>v[100001];
queue<int>q;
int costmin,nod;
int viz[100001];
int n,m,s,x,y;
void bfs(int nods)
{
    for(int j=0;j<v[nods].size();j++)
        {
            if(viz[nods]+1<viz[v[nods][j]] || viz[v[nods][j]]==999999999)
            {
                viz[v[nods][j]]=viz[nods]+1;
                q.push(v[nods][j]);
            }
        }
}
int main()
{
    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    for(int i=1;i<=n;i++)viz[i]=999999999;
    viz[s]=0;
    q.push(s);
    while(!q.empty())
    {
        nod=q.front();
        bfs(nod);
        q.pop();
    }
    for(int i=1;i<=n;i++)
        if(viz[i]==999999999)fout<<-1<<" ";
        else fout<<viz[i]<<" ";
    return 0;
}