Cod sursa(job #3304387)

Utilizator Robert_OprisanRobert Oprisan Robert_Oprisan Data 23 iulie 2025 10:33:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.9 kb
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
ifstream in("bfs.in");
ofstream out("bfs.out");

const int NMAX = 100001;
const int MMAX = 1000001;
int n,m,s;
int distances[NMAX];

vector <int> v[NMAX];
queue <int> q;

void readIn(){
    in >> n >> m >> s;
    for(int i = 0 ; i < m ; i++){
        int x,y;
        in >> x >> y;
        v[x].push_back(y);
    }
}

void bfs(int start){
    for(int i = 1; i <= n;i++){
        distances[i] = -1;
    }
    q.push(start);
    distances[start] = 0;
    while(!q.empty()){
        int node = q.front();
        q.pop();
        int c = distances[node]+1;
        for(auto x :  v[node]){
            if(distances[x]== -1){
                distances[x]= c;
                q.push(x);
            }
        }
    }
}

int main(){
    readIn();
    bfs(s);
    for(int i = 1; i <=n;i++){
        out << distances[i] << " ";
    }
}