Cod sursa(job #2301921)

Utilizator alexoloieriAlexandru Oloieri alexoloieri Data 13 decembrie 2018 17:37:29
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.14 kb
#include <cstdio>
#include <utility>
#include <queue>
#define LMAX 100005
#define mp make_pair
using namespace std;
FILE *fin=fopen("bfs.in", "r");
FILE *fout=fopen("bfs.out", "w");

vector<int> G[LMAX];
int niv[LMAX];
int n, m, start;
bool uz[LMAX];
queue<pair<int, int>>q;
int x, y;

void bfs(int start)
{
    q.push(mp(start,0));
    uz[start] = 1;
    while (!q.empty())
    {
        pair<int,int>act = q.front();
        q.pop();
        niv[act.first] = act.second;
        for (int i =0;i<G[act.first].size();++i)
        {
            if (!uz[G[act.first][i]])
            {
                uz[G[act.first][i]] = 1;
                q.push(mp(G[act.first][i], act.second+1));
            }
        }
    }
}

int main()
{
    fscanf(fin, "%d %d %d", &n, &m, &start);
    for (int i =1;i<=m;++i)
    {
        fscanf(fin, "%d %d",&x,&y);
        G[x].push_back(y);
    }
    for (int i = 1;i<=n;++i)
    {
        niv[i] = -1;
    }
    bfs(start);
    for (int i =1;i<=n;++i)
    {
        fprintf(fout, "%d ", niv[i]);
    }
    fprintf(fout, "\n");
    fclose(fin);
    fclose(fout);
    return 0;
}