Cod sursa(job #1610474)

Utilizator Alex1234Alexandru Posea Alex1234 Data 23 februarie 2016 16:19:07
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <cstdio>
#include <vector>
#include <queue>
#include <climits>

#define inf INT_MAX
#define lim 100001

using namespace std;

vector <int> nods[lim];
vector <int> :: iterator it;
queue <int> q;
int S,N,M,dist[lim],viz[lim],dmin;

FILE *f1,*f2;
int main()
{
    int a,b;
    f1=fopen("bfs.in","r");
    fscanf(f1,"%d%d%d",&N,&M,&S);
    for(int i=1; i<=M; i++)
    {
        fscanf(f1,"%d%d",&a,&b);
        nods[a].push_back(b);
    }
    for(int i=1; i<=N; i++)
    {
        dist[i]=0;
    }
    dist[S]=0;
    q.push(S);
    viz[S]=1;
    while(!q.empty())
    {
        int a=q.front();q.pop();
        dmin=dist[a];
        for(it=nods[a].begin(); it!=nods[a].end(); it++)
        {
            if(!viz[*it])
            {
                viz[*it]=1;
                q.push(*it);
                dist[*it]=dmin+1;
            }
        }
    }
    f2=fopen("bfs.out","w");
    for(int i=1;i<=N;i++)
    {
        if(i!=S)
        fprintf(f2,"%d ",dist[i]!=0?dist[i]:-1);
        else
            fprintf(f2,"0 ");
    }
    return 0;
}