Cod sursa(job #2202545)

Utilizator GeorgianBaditaBadita Marin-Georgian GeorgianBadita Data 9 mai 2018 01:10:14
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.92 kb
#include <fstream>
#include <vector>
#include <queue>
#define NMAX 100005
#define pb push_back
using namespace std;

ifstream f("bfs.in");
ofstream g("bfs.out");

int n, m, start;
vector<int>G[NMAX];
int dist[NMAX];
queue<int> q;

void read_data(int &n, int &m, int& start){
    f >> n >> m >> start;
    for(int i = 1; i<=m; i++){
        int x, y;
        f >> x >> y;
        G[x].pb(y);
    }
}

void bfs(int start){
    for(int i = 1; i<=n; i++){
        dist[i] = -1;
    }
    dist[start] = 0;

    q.push(start);

    while(!q.empty()){
        int node = q.front();
        q.pop();
        for(int i = 0; i<G[node].size(); i++){
            if(dist[G[node][i]] == -1){
                dist[G[node][i]] = 1 + dist[node];
                q.push(G[node][i]);
            }
        }
    }
}

int main(){
    read_data(n, m, start);
    bfs(start);
    for(int i = 1; i<=n; i++){
        g << dist[i] << ' ';
    }
    return 0;
}