Cod sursa(job #2255391)

Utilizator cristicretancristi cretan cristicretan Data 6 octombrie 2018 20:38:15
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.96 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
#define NMax 100001
///#define f cin
///#define g cout
using namespace std;

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

vector<int> G[NMax];
int n, m, x, y, start, L[NMax];
queue<int> q;
bool viz[NMax];

void bfs(int k)
{
    viz[k] = true;
    L[k] = 0;
    q.push(k);
    while(!q.empty())
    {
        int nod = q.front();
        for(int i = 0; i < G[nod].size(); ++i)
            if(!viz[G[nod][i]])
        {
            viz[G[nod][i]] = true;
            L[G[nod][i]] = L[nod] + 1;
            q.push(G[nod][i]);
        }
        q.pop();
    }
}

int main()
{
    f >> n >> m >> start;
    for(int i = 1; i <= m; ++i)
    {
        f >> x >> y;
        G[x].push_back(y);
    }
    for(int i = 1; i <= n; ++i)
        L[i] = -1;
    bfs(start);
    for(int i = 1; i <= n; ++i)
        g << L[i] << " ";
    return 0;
}