Kth smallest number again
https://www.hackerearth.com/practice/algorithms/searching/binary-search/practice-problems/algorithm/kth-smallest-number-again-2/
#include <bits/stdc++.h> using namespace std; void solve() { int n, q; cin >> n >> q; vector<pair<int, int>> v(n); for (auto &it : v) cin >> it.first >> it.second; sort(v.begin(), v.end()); int idx = 0; for (int i = 1; i < n; i++) { if (v[idx].second >= v[i].first) { v[idx].second = max(v[idx].second, v[i].second); } else { idx++; v[idx] = v[i]; } } while (q--) { int k; cin >> k; int ans = -1; for (int i = 0; i <= idx; i++) { if (v[i].