Cod sursa(job #2634739)

Utilizator BogdanFarcasBogdan Farcas BogdanFarcas Data 12 iulie 2020 09:46:35
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <queue>
#include <vector>
#include <cstring>

using namespace std;

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

const int N=1e5+1;

vector<int>v[N];
queue<int>q;
int a[N],cost[N];

int n,m,s,x,y;

void bfs(int start)
{
    int el;
    memset(cost,-1,sizeof(cost));
    q.push(start);
    cost[start]=0;
    while(!q.empty())
    {
        el=q.front();
        q.pop();
        for(int i=0;i<a[el];i++)
        {
            if(cost[v[el][i]]==-1)
            {
                q.push(v[el][i]);
                cost[v[el][i]]=cost[el]+1;
            }
        }
    }
}

int main()
{
    fin>>n>>m>>s;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    for(int i=1;i<=n;i++)
    {
        a[i]=v[i].size();
    }
    bfs(s);
    for(int i=1;i<=n;i++)
    {
        fout<<cost[i]<<" ";
    }
    return 0;
}