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Cod sursa(job #790670)
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
const int MaxN = 100005;
const int oo = 1000000;
vector<int> G[MaxN];
int N, Start, D[MaxN];
queue<int> Q;
void InitBFS(int S) {
for (int X = 1; X <= N; ++X)
D[X] = oo;
D[S] = 0, Q.push(S);
}
void BFS(int S) {
for (InitBFS(S); !Q.empty(); Q.pop()) {
int X = Q.front();
for (vector<int>::iterator Y = G[X].begin(); Y != G[X].end(); ++Y)
if (D[X]+1 < D[*Y])
D[*Y] = D[X]+1, Q.push(*Y);
}
}
void Read() {
freopen("bfs.in", "r", stdin);
int M; scanf("%d %d %d", &N, &M, &Start);
for (; M; --M) {
int X, Y; scanf("%d %d", &X, &Y);
G[X].push_back(Y);
}
}
void Print() {
freopen("bfs.out", "w", stdout);
for (int X = 1; X <= N; ++X) {
if (D[X] == oo)
D[X] = -1;
printf("%d ", D[X]);
}
printf("\n");
}
int main() {
Read();
BFS(Start);
Print();
return 0;
}