Cod sursa(job #1831620)

Utilizator dsergiu05Sergiu Druga dsergiu05 Data 18 decembrie 2016 14:06:52
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.89 kb
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

const int nmax=100000;
vector <int> g[nmax+1];
queue <int> q;
int d[nmax+1];

int n;

void bfs (int src) {
    for (int i=1; i<=n; i++) {
        d[i]=-1;
    }

    d[src]=0;
    q.push(src);

    while (q.empty()==0) {
        int x=q.front();
        q.pop();
        for (int i=0; i<int(g[x].size()); i++) {
            int xn=g[x][i];
            if (d[xn]==-1) {
                d[xn]=d[x]+1;
                q.push(xn);
            }
        }
    }
}

int main () {
    int m, src;
    fin>>n>>m>>src;

    for (int i=1; i<=m; i++) {
        int x, y;
        fin>>x>>y;
        g[x].push_back(y);
    }

    bfs(src);

    for (int i=1; i<=n; i++) {
        fout<<d[i]<<" ";
    }
    fout<<"\n";

    return 0;
}