Pagini recente » Cod sursa (job #1582705) | Cod sursa (job #1077689) | Cod sursa (job #1088571) | Cod sursa (job #2403061) | Cod sursa (job #1980674)
#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>
#include <queue>
#define NMAX 200001
#define INF 2000000000
using namespace std;
bitset <NMAX> in_queue;
vector <int> v[NMAX];
int n;
int dist[NMAX];
inline void bfs(int source) {
for (int i = 1; i <= n; i++)
dist[i] = INF;
queue <int> q;
q.push(source);
dist[source] = 0;
in_queue[source] = 1;
while (q.empty() == 0) {
int node = q.front();
in_queue[node] = 0;
q.pop();
for (auto it : v[node])
if (dist[node] + 1 < dist[it]) {
dist[it] = dist[node] + 1;
if (in_queue[it] == 0){
q.push(it);
in_queue[it] = 1;
}
}
}
}
int main()
{
ifstream f("bfs.in");
ofstream g("bfs.out");
int m, s, x, y;
f >> n >> m >> s;
for (int i = 0; i < m; i++) {
f >> x >> y;
v[x].push_back(y);
}
bfs(s);
for (int i = 1; i <= n; i++)
if (dist[i] != INF)
g << dist[i] << " ";
else
g << -1 << " ";
f.close();
g.close();
return 0;
}