Breadth First Search (Graph Theory)

#include <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <bitset>
#include <vector>
#include <cstdio>
#include <string>
#include <cassert>
#include <climits>
#include <sstream>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
#define PB push_back
#define MP make_pair
#define SZ(v) ((int)(v).size())
#define abs(x) ((x) > 0 ? (x) : -(x))
#define FOREACH(e,x) for(__typeof(x.begin()) e=x.begin();e!=x.end();++e)
typedef long long LL;

const int MAXN = 1000 + 5;
int n, m;
vector<int> adj[MAXN];
int dis[MAXN];
int main() {
int ts;
cin >> ts;
while (ts--) {
cin >> n >> m;
for (int i = 0; i < m; i++) {
int x, y;
cin >> x >> y;
x--; y--;
adj[x].PB(y);
adj[y].PB(x);
}
int s;
cin >> s;
s--;
queue<int> q;
q.push(s);
memset(dis, -1, sizeof(dis));
dis[s] = 0;
while (!q.empty()) {
int u = q.front(); q.pop();
// cout << u << " " << dis[u] << endl;
for (int i = 0; i < adj[u].size(); i++) {
int v = adj[u][i];
if (dis[v] == -1) {
dis[v] = dis[u] + 1;
q.push(v);
}
}
}
for (int i = 0; i < n; i++) {
if (i == s) continue;
printf("%d ", dis[i] == -1 ? dis[i] : dis[i] * 6);
}
puts("");
for (int i = 0; i < n; i++) {
adj[i].clear();
}
}
return 0;
}