Cod sursa(job #1355731)

Utilizator IonSebastianIon Sebastian IonSebastian Data 22 februarie 2015 22:27:13
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.13 kb
#include <cstdio>
#include <queue>

using namespace std;

const int MAX_N = 100000, MAX_M = 1000000;

FILE *in, *out;

int lst[MAX_N+1], urm[MAX_M+1], vf[MAX_M+1];
int nr;

void add(int x, int y)
{
    nr++;
    vf[nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
}

queue<int> q;
bool viz[MAX_N+1];
int d[MAX_N+1];

void bfs()
{
    int x, p;
    while(!q.empty())
    {
        x = q.front();
        q.pop();
        viz[x] = true;
        p = lst[x];
        while(p != 0)
        {
            if(!viz[vf[p]])
            {
                q.push(vf[p]);
                d[vf[p]] = d[x]+1;
                viz[vf[p]] = true;
            }
            p = urm[p];
        }
    }
}

int main()
{
    in = fopen("bfs.in", "r");
    out = fopen("bfs.out","w");
    int n, m, s;
    int x, y;
    fscanf(in, "%d%d%d", &n, &m, &s);
    for(int i = 1; i <= m; i++)
    {
        fscanf(in, "%d%d", &x, &y);
        add(x, y);
    }
    d[s] = 1;
    q.push(s);
    bfs();
    for(int i = 1; i <= n; i++)
        fprintf(out, "%d ", d[i]-1);
    fclose(in);
    fclose(out);
    return 0;
}