Cod sursa(job #1688562)

Utilizator Bodo171Bogdan Pop Bodo171 Data 13 aprilie 2016 16:21:59
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <iostream>
#include<vector>
#include<deque>
#include<fstream>
using namespace std;
vector<int> vecini[100005];
deque<int> q;
int x,y,i,cost[100005],n,m,start,a,b,deparcurs[100005];
void bfs(int x)
{
    for(i=1;i<=n;i++) cost[i]=-1;
    cost[x]=0;
    q.push_back(x);
    while(!q.empty())
    {
        start=q.front();
        q.pop_front();
        for(i=0;i<deparcurs[start];i++)
        {
            if(cost[vecini[start][i]]==-1)
            {
                cost[vecini[start][i]]=cost[start]+1;
                q.push_back(vecini[start][i]);
            }
        }
    }
}
int main()
{
    ifstream f("bfs.in");
    ofstream g("bfs.out");
    f>>n>>m>>x;
    for(i=1;i<=m;i++)
    {
        f>>a>>b;
        vecini[a].push_back(b);
    }
    for(i=1;i<=n;i++)
    {
        deparcurs[i]=vecini[i].size();
    }
 bfs(x);
 for(i=1;i<=n;i++) g<<cost[i]<<' ';
    return 0;
}