Cod sursa(job #1116173)

Utilizator ignadariusIgna Darius ignadarius Data 22 februarie 2014 13:16:17
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.91 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#define nmax 100005
using namespace std;

vector <int> vecin[nmax];
queue <int> q;
int cost[nmax];
int n, m, s, x, y, urmator;


void bfs() {
    while(!q.empty()) {
        int curent = q.front();
        q.pop();

        for(int i=0; i<vecin[curent].size(); i++) {
            urmator = vecin[curent][i];
            if(cost[urmator] == -1) {
                cost[urmator] = cost[curent] + 1;
                q.push(urmator);
            }
        }

    }
}
int main() {
    ifstream f("bfs.in");
    ofstream g("bfs.out");

    f>>n>>m>>s;
    for(int i=1; i<=n; i++) cost[i] =-1;
    cost[s] = 0;

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

    q.push(s);
    bfs();

    for(int i=1; i<=n; i++)
        g<<cost[i]<<" ";


    return 0;
}