Cod sursa(job #2237088)

Utilizator sorynsooSorin Soo sorynsoo Data 31 august 2018 16:04:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.87 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

#define MAXN 100005
#define INF 0x3f3f3f3f

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

    vector<int> dist(n + 5, INF);
    vector<int> graf[MAXN];
    for(int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        graf[x].push_back(y);
    }

    queue<int> q;
    q.push(s);
    dist[s] = 0;

    while(!q.empty()) {
        int crtNode = q.front(); q.pop();

        for(auto nextNode: graf[crtNode]) {
            if(dist[nextNode] > dist[crtNode] + 1) {
                dist[nextNode] = dist[crtNode] + 1;
                q.push(nextNode);
            }
        }
    }

    for(int i = 1; i <= n; i++) {
        if(dist[i] == INF)
            fout << "-1 ";
        else
            fout << dist[i] << " ";
    }

    return 0;
}