Cod sursa(job #2298364)

Utilizator danin01Nastase Daniel danin01 Data 8 decembrie 2018 08:42:04
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.18 kb
#include <fstream>
#include <queue>
#include <vector>
#include <iostream>

using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

int n,m,s,dist[100001];

bool viz[100001];

vector<int>a[100001];

void bfs(int src)
{

    queue<int>q;
    q.push(src);

    while(!q.empty())
    {
        int nod = q.front();
        q.pop();
        for(int i=0;i<a[nod].size();++i)
        {

            if(!viz[a[nod][i]])
            {
                viz[a[nod][i]]=true;
                q.push(a[nod][i]);
                dist[a[nod][i]]=dist[nod]+1;

            }

        }

    }

}

int main()
{
    f>>n>>m>>s;
    viz[s]=true;
    for(int i=1;i<=m;++i)
    {

        int x,y;
        f>>x>>y;
        if(x!=y)a[x].push_back(y);

    }
    bfs(s);
    for(int i=1;i<s;++i)
    {

        if(!dist[i])
        {
            g<<"-1 ";
        }
        else
        {

            g<<dist[i]<<" ";

        }

    }
    g<<"0 ";
    for(int i=s+1;i<=n;++i)
    {

        if(!dist[i])
        {
            g<<"-1 ";
        }
        else
        {

            g<<dist[i]<<" ";

        }

    }
    return 0;
}