Cod sursa(job #361293)

Utilizator curcubeuPop Simina curcubeu Data 4 noiembrie 2009 15:36:48
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.09 kb
#include <iostream>
#include <vector>
#include <fstream>
#define MAXN 100010
using namespace std;
 
vector<int> A[MAXN];
int Cost[MAXN],C[MAXN];
 
int N,M,S;
 
ifstream fin("bfs.in");
ofstream fout("bfs.out");
 
int BFS(int x) {
    int prim,ultim,i;
     
    memset(Cost,-1,sizeof(Cost));
     
    Cost[x] = 0;   
        prim = ultim = 0;
    C[0] = x;
     
    while (prim <= ultim) {
        x = C[prim++];
        for (i=1;i<=A[x][0];++i) {
            if (Cost[A[x][i]] == -1) {
                Cost[A[x][i]] = Cost[x] + 1;
                C[++ultim] = A[x][i];
            }
        }
    }
     
}
 
int main() {
    int x,y,i;
    fin >> N >> M >> S;
     
    for (i=1;i<=N;++i) {
        A[i].push_back(0);
    }
     
    for (i=1;i<=M;++i) {
        fin >> x >> y;
        A[x].push_back(y);
    }
     
    for (i=1;i<=N;++i) {
        A[i][0] = A[i].size() - 1;
    }
     
    BFS(S);
     
    for (i=1;i<=N;++i)
        fout << Cost[i] << " ";
         
    fout << endl;
 
    fin.close();
    fout.close();
     
    return 0;
}