Cod sursa(job #1691958)

Utilizator GeorginskyGeorge Georginsky Data 19 aprilie 2016 21:17:15
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.83 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define NMAX 100001
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");
int n, m, s, i, j, x, y, v[NMAX], d[NMAX];
vector<int> nodes[NMAX];
queue<int> q;
void read(){
    in>>n>>m>>s;
    for(i=1; i<=m; i++){
        in>>x>>y;
        nodes[x].push_back(y);
        if(i<=n)d[i]=-1;
    }
}

void bfs(){
    q.push(s);
    v[s]=1;
    d[s]=0;
    while(!q.empty()){
        x=q.front();
        q.pop();
        for(i=0; i<nodes[x].size(); i++){
            if(v[nodes[x][i]]==0){
                q.push(nodes[x][i]);
                v[nodes[x][i]]=1;
                d[nodes[x][i]]=d[x]+1;
            }
        }
    }
    for(i=1; i<=n; i++)out<<d[i]<<" ";
}
int main(){
    read();
    bfs();
    return 0;
}