145 lines
3.0 KiB
C++

/* Problem URL: https://codeforces.com/contest/2149/problem/G */
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T, class comp = less<>>
using ordered_set = tree<T, null_type , comp , rb_tree_tag , tree_order_statistics_node_update>;
#define V vector
#define rmin(a, b) a = min(a, b)
#define rmax(a, b) a = max(a, b)
#define rep(i, lim) for (int i = 0; i < (lim); i++)
#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
#define repv(i, v) for (auto &i : (v))
#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
#define sortv(v) sort(v.begin(), v.end())
#define all(v) (v).begin(), (v).end()
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vvvvi = vector<vvvi>;
using ll = long long;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vvvvl = vector<vvvl>;
template<class v>
auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
os << vec[0];
for (size_t i = 1; i < vec.size(); i++) {
os << ' ' << vec[i];
}
os << '\n';
return os;
}
template<class v>
auto operator>>(istream &is, vector<v> &vec)->istream& {
for (auto &i : vec) {
is >> i;
}
return is;
}
template<class v>
auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
for (auto &i : vec) {
os << i[0];
for (size_t j = 1; j < i.size(); j++) {
os << ' ' << i[j];
}
os << '\n';
}
return os;
}
template<class v>
auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
for (auto &i : vec) {
for (auto &j : i) {
is >> j;
}
}
return is;
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(nullptr);
mt19937 seed(chrono::steady_clock::now().time_since_epoch().count());
int t;
cin >> t;
while (t--) {
int n, q;
cin >> n >> q;
vl fds(n);
map<ll, int> var;
repv(i, fds) {
cin >> i;
var[i] = 0;
}
int v = 0;
vi inv(var.size());
repv(i, var) {
i.second = v;
inv[v] = i.first;
v++;
}
vvi pos(var.size());
rep(i, n) {
fds[i] = var[fds[i]];
pos[fds[i]].push_back(i);
}
while (q--) {
set<int> ans;
int l, r;
cin >> l >> r;
l--, r--;
uniform_int_distribution<> rng(l, r);
int lim = (r - l + 1) / 3;
rep(i, 50) {
int now = rng(seed);
int count = upper_bound(all(pos[fds[now]]), r) - lower_bound(all(pos[fds[now]]), l);
if (count > lim) {
ans.insert(inv[fds[now]]);
}
}
if (ans.empty()) {
cout << "-1\n";
}
repv(i, ans) {
cout << i << ' ';
}
cout << '\n';
}
}
}