Cod sursa(job #2739906)

Utilizator RobertAcAcatrinei Robert-Marian RobertAc Data 10 aprilie 2021 15:47:31
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.85 kb
#include <bits/stdc++.h>

using namespace std;

ifstream in("bfs.in");
ofstream out("bfs.out");
queue<int> q;
vector<vector<int>>g(100001);
vector<int> rez(100001);
vector<bool> v(100001);

void bfs(int s){
    while(!q.empty()){
        int n=q.front();
        q.pop();
        for(auto i:g[n]){
            if(!v[i])q.push(i);
            if(i!=s){
                if(rez[i]==0){
                rez[i]=rez[n]+1;
                }else{
                    if(rez[i]>rez[n]+1)rez[i]=rez[n]+1;
                }
            }

        }

    }
}

int main(){
    int n,m,s;
    in>>n>>m>>s;
    for(int i=0;i<m;i++){
        int x,y;
        in>>x>>y;
        g[x].push_back(y);
    }
    q.push(s);
    v[s]=1;
    bfs(s);
    for(int i=1;i<=n;i++){
        if(rez[i]==0&&i!=s)rez[i]=-1;
        out<<rez[i]<<" ";
    }


}