Cod sursa(job #1935643)

Utilizator Horia14Horia Banciu Horia14 Data 22 martie 2017 16:15:23
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include<cstdio>
#include<vector>
#include<queue>
#define N_MAX 100000
using namespace std;

vector<int>v[N_MAX+1];
queue<int>Q;
int d[N_MAX+1], n, m, S;

void Read()
{
    int i, x, y;
    FILE *fin = fopen("bfs.in","r");
    fscanf(fin,"%d%d%d",&n,&m,&S);
    for(i=1; i<=m; i++)
    {
        fscanf(fin,"%d%d",&x,&y);
        v[x].push_back(y);
    }
    fclose(fin);
}

void BFS(int x)
{
    int i, nod;
    for(i=1; i<=n; i++)
        d[i] = -1;
    d[x] = 0;
    Q.push(x);
    while(!Q.empty())
    {
        nod = Q.front();
        Q.pop();
        for(vector<int>::iterator it = v[nod].begin(); it!=v[nod].end(); it++)
            if(d[*it] == -1)
            {
                d[*it] = d[nod] + 1;
                Q.push(*it);
            }
    }
}

void Write()
{
    FILE *fout = fopen("bfs.out","w");
    for(int i=1; i<=n; i++)
        fprintf(fout,"%d ",d[i]);
    fprintf(fout,"\n");
    fclose(fout);
}

int main()
{
    Read();
    BFS(S);
    Write();
    return 0;
}