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Cod sursa(job #863496)
#include <cstdio>
#include <cstring>
#include <vector>
#include <queue>
#include <bitset>
using namespace std;
#define Nmax 100001
bitset <Nmax> viz;
vector <int> Graf[Nmax];
queue <int> Q;
int dist[Nmax];
int N, M, R;
int a, b;
void citire(){
freopen("bfs.in", "r", stdin);
scanf("%d %d %d", &N, &M, &R);
for(; M; M--){
scanf("%d %d", &a, &b);
Graf[a].push_back(b);
}
}
void init(){
dist[R] = 0;
Q.push(R);
viz[R] = 1;
}
void bfs(){
while(!Q.empty()){
int current = Q.front();
Q.pop();
vector <int> ::iterator it;
for(it = Graf[current].begin(); it != Graf[current].end(); ++it)
if(!viz[*it]){
dist[*it] = dist[current] + 1;
viz[*it] = 1;
Q.push(*it);
}
}
for(int i = 1; i <= N; i++)
if(dist[i] == 0 && i != R)
dist[i] = -1;
}
void afis(){
freopen("bfs.out", "w", stdout);
for(int i = 1; i<= N; i++)
printf("%d ", dist[i]);
}
int main(){
citire();
init();
bfs();
afis();
return 0;
}