Pagini recente » Cod sursa (job #788200) | Cod sursa (job #2824150) | Cod sursa (job #251058) | Cod sursa (job #1353118) | Cod sursa (job #1563263)
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int n, m, S;
vector<vector<int>> G;
vector<int> v;
vector<bool> s;
queue<int> Q;
void Read();
void BFS();
void Write();
int main() {
Read();
BFS();
Write();
fin.close();
fout.close();
return 0;
}
void BFS() {
Q.push(S);
int x;
while (!Q.empty()) {
x = Q.front(); Q.pop();
s[x] = true;
for (const auto & e: G[x])
if (!s[e]) {
Q.push(e);
v[e] = v[x] + 1;
}
}
}
void Write() {
for (int i = 1; i <= n; i++)
if (v[i] == 0 && i != S) fout << "-1 ";
else fout << v[i] << ' ';
}
void Read() {
fin >> n >> m >> S;
G = vector<vector<int>>(n + 1);
v = vector<int>(n + 1);
s = vector<bool>(n + 1);
for (int i = 0, x, y; i < m; i++) {
fin >> x >> y;
G[x].push_back(y);
}
}