Cod sursa(job #1774324)

Utilizator raulrusu99Raul Rusu raulrusu99 Data 8 octombrie 2016 20:02:46
Problema BFS - Parcurgere in latime Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
vector <int> v[100010];
queue <int> q;
bool viz[100010];
int dist[100010];
int n,m,s;
void dfs(int start)
{
    viz[start]=1;
    dist[start]=0;
    q.push(start);
    int nod;
    while(!q.empty())
    {
        nod=q.front();
        q.pop();
        for(auto it:v[nod])
        {
            if(!viz[it])
            {
                q.push(it);
                viz[it]=1;
                dist[it]=dist[nod]+1;
            }
        }
    }
}
int main()
{
    int st=-1;
    f>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x;
        f>>y;
        if(x==y && x==s)
            st=0;
        else
            v[x].push_back(y);
    }
    dfs(s);
    for(int i=1;i<=n;i++)
        if(i==s)
            g<<st<<" ";
        else
            if(dist[i]==0) g<<-1<<" ";
        else
            g<<dist[i]<<" ";
    return 0;
}