Submission #511125

#	Time	Username	Problem	Language	Result	Execution time	Memory
511125		Mazaalai	Gift (IZhO18_nicegift)	C++17	30 / 100	2066 ms	164416 KiB

nicegift

#include <bits/stdc++.h>
#define pb push_back
#define ff first
#define ss second
#define LLA(x) x.rbegin(),x.rend()
#define print(x) for(auto el:x)cout<<el<<' ';cout<<"\n";
#define printPII(x) for(auto [a,b]:x)cout<<a<<","<<b<<' ';cout<<'\n';
using namespace std;
using ll = long long;
using PII = pair <ll, ll>;
ll n, k, onePick = 1;
bool impossible;
signed main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	// freopen("in.txt", "r", stdin);
	// freopen("out.txt", "w", stdout);
	cin >> n >> k;
	vector <vector <ll> > ans;
	set <PII> bfs;
	ll sum = 0, dbg = 0;
	for (int i = 1; i <= n; i++) {
		ll x; cin >> x;
		sum += x;
		bfs.insert({x, i});
	}
	if (sum % k != 0) {
		cout << "-1\n";
		return 0;
	}
	while(!impossible && sum > 0) {
		vector <ll> pick;
		vector <PII> add;
		for (int i = 0; i < k; i++) {
			auto it = --bfs.end();
			PII cur = *it;
			bfs.erase(it);
			pick.pb(cur.ss);
			if (cur.ff < 0) {
				impossible = 1;
				break;
			}
			add.pb(cur);
		}
		ll mini = add[0].ff, And = add[0].ff;
		for (int i = 1; i < k; i++) {
			mini = min(mini, add[i].ff);
			And &= add[i].ff;
		}
		ll mxBit = 1;
		for (int i = 1; i < 60; i++) 
			if (mini & (1ll<<i)) mxBit = i;
		
		mxBit = (1<<(mxBit-1));
		if (And * k == sum) mxBit = And;
		pick.pb(mxBit);
		swap(pick[0], pick.back());
		for (auto& [a, b] : add) {
			a -= mxBit;
			sum -= mxBit;
			bfs.insert({a, b});
		}
		ans.pb(pick);
		// for (auto& [a, b] : bfs) {
		// 	cout << a << ',' << b << ' ';
		// }
		// cout << '\n';
		// if (dbg++ == 30) break;
	}
	// int dbg = 0;
	if (impossible) {
		cout << "-1\n";
		return 0;
	}
	cout << ans.size() << '\n';
	for (auto el : ans) {
		print(el);
	}
}

Compilation message (stderr)

nicegift.cpp: In function 'int main()':
nicegift.cpp:22:14: warning: unused variable 'dbg' [-Wunused-variable]
   22 |  ll sum = 0, dbg = 0;
      |              ^~~

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 51