Cod sursa(job #1545529)

Utilizator RathebaSerbanescu Andrei Victor Ratheba Data 6 decembrie 2015 20:25:37
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

const int MAX = 100003;

vector<int> v[MAX];
queue<int> q;
int n, m, drum[MAX];

void bfs(int source);

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);
    int s, a, b;
    scanf("%d%d%d", &n, &m, &s);
    for(int i=1; i<=m; i++)
    {
        scanf("%d%d", &a, &b);
        v[a].push_back(b);
    }
    bfs(s);
    for(int i=1; i<=n; i++)
        printf("%d ", drum[i]);
    return 0;
}
void bfs(int source)
{
    int tata, fiu;
    for(int i=1; i<=n; i++)
        drum[i] = -1;
    drum[source] = 0;
    q.push(source);
    while(!q.empty())
    {
        tata = q.front();
        q.pop();
        vector<int>::iterator it;
        for(it=v[tata].begin(); it!=v[tata].end(); ++it)
        {
            fiu = *it;
            if(drum[fiu] == -1)
            {
                drum[fiu] = drum[tata] + 1;
                q.push(fiu);
            }
        }
    }
}