#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> // using mint = modint998244353; template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } using mint = modint998244353; void debug_mint1(vector &vec) { for (int i = 0; i < vec.size(); i++) { cerr << vec[i].val() << " "; } cerr << endl; } void debug_mint2(vector> &vec) { for (int i = 0; i < vec.size(); i++) { for (int j = 0; j < vec[i].size(); j++) { cerr << vec[i][j].val() << " "; } cerr << endl; } } pair, vector> convex_hull(ll N, vector &X, vector &Y) { vector p(N); for (ll i = 0; i < N; i++) { p[i].first = X[i]; p[i].second = Y[i]; } sort(all(p)); // debug(p); // 上側凸包 vector upper_ch(0); vector lower_ch(0); ll len = 0; for (ll i = 0; i < N; i++) { if (len < 2) { upper_ch.push_back(i); len++; } else { while (len >= 2) { ll v2 = upper_ch[len - 2]; ll v1 = upper_ch[len - 1]; if ((p[i].first - p[v1].first) * (p[v2].second - p[v1].second) - (p[v2].first - p[v1].first) * (p[i].second - p[v1].second) >= 0) { upper_ch.pop_back(); len--; } else { break; } } upper_ch.push_back(i); len++; } } len = 0; for (ll i = 0; i < N; i++) { if (len < 2) { lower_ch.push_back(i); len++; } else { while (len >= 2) { ll v2 = lower_ch[len - 2]; ll v1 = lower_ch[len - 1]; if ((p[i].first - p[v1].first) * (p[v2].second - p[v1].second) - (p[v2].first - p[v1].first) * (p[i].second - p[v1].second) <= 0) { lower_ch.pop_back(); len--; } else { break; } } lower_ch.push_back(i); len++; } } return pair, vector>(upper_ch, lower_ch); } int main() { ll T; cin >> T; while (T--) { ll N; cin >> N; vector X(N); vector Y(N); for (ll i = 0; i < N; i++) { cin >> X[i] >> Y[i]; } vector> p(N); for (ll i = 0; i < N; i++) { p[i].first.first = X[i]; p[i].first.second = Y[i]; p[i].second = i; } sort(all(p)); vector idxs(N); for (ll i = 0; i < N; i++) { idxs[i] = p[i].second; } debug(idxs); vector isonch(N, false); pair, vector> ch = convex_hull(N, X, Y); vector upper_ch = ch.first; vector lower_ch = ch.second; vector loop_ch(0); for (ll i = 0; i < upper_ch.size(); i++) { loop_ch.push_back(idxs[upper_ch[i]]); } for (ll i = lower_ch.size() - 2; i >= 1; i--) { loop_ch.push_back(idxs[lower_ch[i]]); } debug(loop_ch); ll INF = 100000000000023; vector A(N, INF); vector B(N, INF); if (loop_ch.size() == 2) { vector dx = {1, 0, -1, 0}; vector dy = {0, 1, 0, -1}; for (ll i = 0; i < 4; i++) { if (X[loop_ch[0]] * dx[i] + Y[loop_ch[0]] * dy[i] > X[loop_ch[1]] * dx[i] + Y[loop_ch[1]] * dy[i]) { A[loop_ch[0]] = dx[i]; B[loop_ch[0]] = dy[i]; A[loop_ch[1]] = -dx[i]; B[loop_ch[1]] = -dy[i]; break; } } } else { ll len_ch = loop_ch.size(); for (ll i = 0; i < len_ch; i++) { ll id1 = (i + 1) % len_ch; ll id2 = (i + len_ch - 1) % len_ch; A[loop_ch[i]] = -(Y[loop_ch[id1]] - Y[loop_ch[id2]]); B[loop_ch[i]] = (X[loop_ch[id1]] - X[loop_ch[id2]]); } } for (ll i = 0; i < N; i++) { if (A[i] == INF) { cout << "No" << endl; } else { cout << A[i] << " " << B[i] << endl; } } } }