Cod sursa(job #2235988)

Utilizator ale.sicobeanAlexandra Sicobean ale.sicobean Data 27 august 2018 15:52:19
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <iostream>
#include <fstream>
#define INF 0x3f3f3f3f
#include <bits/stdc++.h>
using namespace std;

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

vector <int> v[100005];
queue <int> q;

int n,m,i,s,cost[100005];

void bfs()
{
    while(!q.empty())
    {
        int nod=q.front();
        q.pop();
        for(auto it=v[nod].begin();it!=v[nod].end();it++)
        {
            int nxt=*it;
            if(cost[nod]+1<cost[nxt])
            {
                q.push(nxt);
                cost[nxt]=cost[nod]+1;
            }
        }
    }
}

int main()
{
    fin>>n>>m>>s;
    memset(cost,INF,sizeof(cost));
    for(i=1;i<=m;i++)
    {
        int x,y;
        fin>>x>>y;
        v[x].push_back(y);
    }
    cost[s]=0;
    q.push(s);
    bfs();
    for(i=1;i<=n;i++)
    {
        if(cost[i]==INF)
            fout<<-1<<" ";
        else
            fout<<cost[i]<<" ";
    }
    return 0;
}