Cod sursa(job #2369741)

Utilizator Anastasia11Susciuc Anastasia Anastasia11 Data 6 martie 2019 09:04:45
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.94 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <cstring>
#define Nmax 100005
#define INF 0x3f3f3f3f

using namespace std;

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

int n, m, s, x, y;
int d[Nmax];
vector <int> v[Nmax];
queue <int> Q;

void bfs(int start)
{
    memset(d, INF, sizeof(d));
    // for (int i = 1; i <= n; i++) d[i]=INF;
    d[start]=0;
    Q.push(start);
    while(!Q.empty())
    {
        int x=Q.front();
        Q.pop();
        for (auto y:v[x])
        {
            if(d[y]>d[x]+1)
            {
                d[y]=d[x]+1;
                Q.push(y);
            }
        }
    }
    for (int i = 1; i <= n; i++)
        if(d[i] == INF) g << "-1 ";
    else
        g << d[i] << " ";
}

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

    return 0;
}