Cod sursa(job #873507)

Utilizator BeilandArnoldArnold Beiland BeilandArnold Data 7 februarie 2013 12:11:25
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.94 kb
#include <fstream>
#include <list>
#include <vector>
#include <queue>

int main(){
    std::ifstream fin("bfs.in");
    std::ofstream fout("bfs.out");

    unsigned N,M,S;
    fin>>N>>M>>S;
    std::vector< std::vector<unsigned> > liste(M,std::vector<unsigned>(N));
    std::vector<unsigned> index(M,0);
    for(unsigned i=0;i<M;++i){
        unsigned a,b;
        fin>>a>>b;
        if(b!=S) liste[a-1][index[a-1]++]=b-1;
    }

    std::vector<int> cost(N,-1);
    std::queue<unsigned> sor;

    cost[S-1]=0;
    sor.push(S-1);

    for(unsigned i=0;i<index.size();++i) index[i]=0;
    while(!sor.empty()){
        S=sor.front(); sor.pop();
        for(;index[S]<liste[S].size();index[S]++){
            M=liste[S][index[S]];
            if(cost[M]==-1){
                cost[M]=cost[S]+1;
                sor.push(M);
            }
        }
    }

    for(unsigned i=0;i<N;++i) fout<<cost[i]<<' ';
    fout<<'\n';
}