Cod sursa(job #3286913)

Utilizator suimerchantsui merchant suimerchant Data 14 martie 2025 19:59:31
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.87 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

#if 1
ifstream fin("bfs.in");
ofstream fout("bfs.out");
#else
#define fin cin
#define fout cout
#endif

int n,m,s;

vector <int> v[100005];
queue <pair<int,int>> q;
int d[100005];

void bfs()
{
    for(auto it:v[s]) q.push({it,1});
    while(!q.empty())
    {
        int vec=q.front().first;
        int lg=q.front().second;
        q.pop();
        if(vec!=s && !d[vec])
        {
            d[vec]=lg;
            for(auto it:v[vec])if(!d[it] && it!=s)q.push({it,lg+1});
        }
    }
    for(int i=1;i<=n;i++)
    {
        if(!d[i] && i!=s)fout<<"-1 ";
        else fout<<d[i]<<" ";
    }
}

int main()
{
    fin>>n>>m>>s;
    int x,y;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
    }
    bfs();
}