Cod sursa(job #2073731)

Utilizator sebistetuCucolas Sebastian sebistetu Data 23 noiembrie 2017 16:57:00
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include<fstream>
#include<list>
#include<queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
list<int>l[100005];
queue<int>c;
bool viz[100005];
int cost[100005];
int n, m, nr_comp, s;
void citire()
{
    f >> n >> m >> s;
    int x, y;
    while(f >> x >> y)
        l[x].push_back(y);
}
void bfs(){
    c.push(s);
    viz[s] = 1;
    cost[s] = 0;
    while(!c.empty()){
        int nc = c.front();
        list<int>::iterator it;
        for(it = l[nc].begin(); it != l[nc].end(); it++){
            if(!viz[*it]){
                cost[*it] = cost[nc] + 1;
                c.push(*it);
                viz[*it] = true;
            }
        }
        c.pop();
    }
    for(int i = 1; i <= n; i++)
        if(cost[i] == 0)
            cost[i] = -1;
}
void solve(){
    bfs();
    cost[s] = 0;
    for(int i = 1; i <= n; i++)
        g << cost [i] << ' ';
}
int main(){
    citire();
    solve();
    return 0;
}