Cod sursa(job #1747112)

Utilizator SaitamaSaitama-san Saitama Data 24 august 2016 15:29:54
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <bits/stdc++.h>
#define INF 2000000000
#define Nmax 100005

using namespace std;

ifstream fin("bfs.in");
ofstream fout("bfs.out");

int n, m, S;
vector <int> L[Nmax];
queue <int> q;
int dp[Nmax];

void BFS()
{
    while(!q.empty())
    {
        int nod = q.front();
        q.pop();
        for(auto it : L[nod])
            if(dp[it] > dp[nod] + 1)
            {
                dp[it] = dp[nod] + 1;
                q.push(it);
            }
    }
}

int main()
{
    int i, x, y;
    fin >> n >> m >> S;
    for(i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
    }
    q.push(S);
    for(i = 1; i <= n; i++)
        dp[i] = INF;
    dp[S] = 0;
    BFS();
    for(i = 1; i <= n; i++)
        if(dp[i] == INF)
            fout << "-1 ";
        else fout << dp[i] << " ";
    return 0;
}