Cod sursa(job #2534815)

Utilizator marius004scarlat marius marius004 Data 30 ianuarie 2020 22:50:44
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.83 kb
#include <fstream>
#include <vector>
#include <queue>

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

const int NMAX = 100'005;
int n,m,nodStart,x,y,d[NMAX];

std::vector<int>L[NMAX];
std::queue<int>Q;

void bfs(){
    
    while(!Q.empty()){
        
        int nod = Q.front();
        Q.pop();
        
        for(int vecin : L[nod]){
            if(d[vecin] == -1){
                Q.push(vecin);
                d[vecin] = d[nod] + 1;
            }
        }
    }
}

int main(){
    
    f >> n >> m >> nodStart;
    
    for(int i = 1;i <= m;++i){
        
        f >> x >> y;
        
        L[x].push_back(y);
    }
    
    for(int nod = 1;nod <= n;++nod)
        d[nod] = -1;
    
    d[nodStart] = 0;
    Q.push(nodStart);
    
    bfs();
    
    for(int nod = 1;nod <= n;++nod)
        g << d[nod] << ' ';
    
    return 0;
}