Cod sursa(job #3242669)

Utilizator Alexandru_cioAlexandru Ciobanica Alexandru_cio Data 13 septembrie 2024 08:40:55
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.03 kb
#include <bits/stdc++.h>

using namespace std;

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

const int NMAX=1e5;
const int INF=1e9;
vector<int> G[NMAX+1];
int vis[NMAX+1];
int d[NMAX+1];
queue<int> q;
int n,m,start;

void bfs(int start)
{
    for(int i=1;i<=n;i++)
    {
        d[i]=INF;
    }
    d[start]=0;
    q.push(start);
    vis[start]=1;
    while(!q.empty())
    {
        int node=q.front();
        q.pop();
        for(int i=0;i<G[node].size();i++)
        {
            int vecin=G[node][i];
            if(vis[vecin]==0&&d[vecin]>d[node]+1)
            {
                vis[vecin]=1;
                d[vecin]=d[node]+1;
                q.push(vecin);
            }
        }
    }
}

int main()
{

    f>>n>>m>>start;
    for(int i=1;i<=m;i++)
    {
        int x,y;
        f>>x>>y;
        G[x].push_back(y);
    }
    bfs(start);
    for(int i=1;i<=n;i++)
    {
        if(d[i]==INF)
            g<<"-1"<<" ";
        else
            g<<d[i]<<" ";
    }
    return 0;
}