Cod sursa(job #839458)

Utilizator mvcl3Marian Iacob mvcl3 Data 21 decembrie 2012 20:51:58
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.19 kb
#include<fstream>
#include<vector>
#include<queue>
#define INF 10000000
#define NMAX 100009
using namespace std;
ifstream f("bfs.in"); ofstream g("bfs.out");
int n, m, t, nod_a, nod_b, viz[NMAX];
struct nod
{
    int v;
    int c;
    nod(){};
    nod(int a, int b)
    {
        v = a;
        c = b;
    };
};
queue<int>q;
vector<nod> x[NMAX];
inline void citire();
inline void bfs(int);
int main()
{
    citire();
    bfs(t);
    for(int i = 1; i <= n; ++i)
        if(viz[i] != INF)
            g<<viz[i]<<' ';
        else
            g<<-1<<' ';
    g.close();
    return 0;
}
inline void citire()
{
    f>>n>>m>>t;
    for(int i = 1; i <= m; ++i)
    {
        f>>nod_a>>nod_b;
        x[nod_a].push_back(nod(nod_b, 1));
        if(i <= n) viz[i] = INF;
    }
    f.close();
}
inline void bfs(int k)
{
    q.push(k);
    viz[k] = 0;
    while(!q.empty())
    {
        k = q.front(); q.pop();
        vector<nod>::iterator it;
        for(it = x[k].begin(); it != x[k].end(); ++it)
            if((*it).c + viz[k] < viz[(*it).v])
            {
                viz[(*it).v] = (*it).c + viz[k];
                q.push((*it).v);
            }
    }
}