Cod sursa(job #2629327)

Utilizator Ionut_neuer58Raducu Ioan Stefan Ionut_neuer58 Data 20 iunie 2020 09:39:43
Problema BFS - Parcurgere in latime Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.81 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

vector <int> v[100001];
queue <int> bfsq;
int d[100001];
bool viz[100001];
int n, m, st, yy, xx, nod;

void readit()
{
    in>>n>>m>>st;
    while(m--) in>>yy>>xx, v[yy].push_back(xx);
    bfsq.push(st);
}

void BFS()
{
    while(!bfsq.empty())
    {
        nod=bfsq.front();
        bfsq.pop();
        if(!viz[nod])
        {
            viz[nod]=1;
            for(int i=0; i<v[nod].size(); i++)
                if(!viz[v[nod][i]]) bfsq.push(v[nod][i]), d[v[nod][i]]=d[nod]+1;
        }
    }
}

int main()
{
    readit();
    BFS();
    for(int i=1; i<=n; i++)
        if(!viz[i]) out<<"-1 ";
    else out<<d[i]<<' ';
    return 0;
}