#include <bits/stdc++.h> #include "books.h" using namespace std; typedef long long ll; void solve(int n, int k, ll s, int c) { vector < int > ans, pos; ll a[n + 1], cur = 0; for(int i = 1; i <= n; i++) a[i] = skim(i); for(int i = 1; i <= n; i++){ if(s <= a[i] && a[i] <= 2 * s){ answer({i}); return; } } for(int i = n; i >= 1; i--) if(a[i] < s && pos.size() < k) pos.push_back(i); if(pos.size() < k) { impossible(); return; } for(int i = 1; i < pos[k - 1] && i <= k; i++) pos.push_back(i); for(int msk = 0; msk < (1 << (int)pos.size()); msk++){ if(__builtin_popcount(msk) != k) continue; for(int i = 0; i < pos.size(); i++) if((msk >> i & 1)) cur += a[pos[i]], ans.push_back(pos[i]); if(s <= cur && cur <= 2 * s){ answer(ans); return; } cur = 0, ans.clear(); } impossible(); }