Cod sursa(job #2870676)

Utilizator Popa_IarinaIarina Popa Popa_Iarina Data 12 martie 2022 14:57:12
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.89 kb
#include <iostream>
#include <vector>
#include <deque>
#include <fstream>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector <int>v[100005];
deque<int>dq;
int n,m,start,i,cost[100005],viz[100005],x,y;
void bfs(int start)
{
    int p;
    viz[start]=1;
    dq.push_back(start);
    while(!dq.empty())
    {
        p=dq.front();
        dq.pop_front();
        for(auto it=v[p].begin(); it!=v[p].end(); it++)
            if(!viz[*it])
            {
                viz[*it]=1;
                dq.push_back(*it);
                cost[*it]=cost[p]+1;
            }
    }
}

int main()
{
    fin>>n>>m>>start;
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    for(i=1; i<=n; i++)
        cost[i]=-1;
    cost[start]=0;
    bfs(start);
    for(i=1; i<=n; i++)
        fout<<cost[i]<<' ';
    return 0;
}