Submission #1154305

#	Time	Username	Problem	Language	Result	Execution time	Memory
1154305		KluydQ	Gift (IZhO18_nicegift)	C++20	7 / 100	508 ms	85240 KiB

nicegift

#include <bits/stdc++.h>

#define respagold ios_base::sync_with_stdio(0), cin.tie(0);
#define int long long
#define ll long long
#define int2 __int128_t
#define FOR( i, x, n, d ) for( int i = x; i <= n; i += d )
#define FORR( i, x, n, d ) for( int i = x; i >= n; i -= d )
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x.size())
#define pb push_back
#define ins insert
#define lb lower_bound
#define ub upper_bound
#define pii pair <int, int>
#define mkp make_pair
 
using namespace std;
 
const int N = 1e6 + 123;
const int inf = 1e18;
const int mod = 1e9 + 7;
 
int a[N], b[N], c[N], n, m, q, k, z, w, x, y;

mt19937 rng( chrono::steady_clock::now().time_since_epoch().count());
 
int rand( int l, int r )
{
    uniform_int_distribution <int> uid( l, r );
    return uid( rng );
}
vector <vector <int>> ans;
vector <int> sv, v;

void solve()
{
	cin >> n >> k;
	
	multiset <pii> st;
	FOR( i, 1, n, 1 ) cin >> a[i], x += a[i], st.ins({ a[i], i });
	
	if( x % k || (*st.rbegin()).F > x / k )
	{
		cout << "-1\n";
		return;
	}
	bool red = 0;
	
	while( 1 )
	{
		v.clear();
		while( sz(v) < k && sz(st) ) v.pb( (*st.rbegin()).S ), st.erase( st.find( *st.rbegin() ));
		
		int cc = a[v.back()];
		sv.clear();
		int bob = x / k - a[v[0]] + cc;
		if( sz(st) ) bob = max( bob, x / k - (*st.rbegin()).S );
		cc = min( cc, bob );
		sv.pb(cc);
		
		if( cc == 0 && a[v[0]] )
		{
			cout << -1;
			return;
		}
		x -= cc * k;
		
		for( auto i : v )
		{
			a[i] -= cc;
			if( a[i] > 0 ) st.ins({ a[i], i });
			sv.pb(i);
		}
		ans.pb(sv);
		if( sz(st) == 0 ) break;
	}
	cout << sz(ans) << '\n';
	
	for( auto i : ans )
	{
		for( auto j : i ) cout << j << ' ';
		cout << '\n';
	}
}
signed main() 
{
//	freopen("connect.in", "r", stdin);
//	freopen("connect.out", "w", stdout);
	    
    respagold
    
    int test = 1;
    
    if( !test ) cin >> test;
	
	while( test -- )
	{
		solve();
	}
}
// solved by KluydQ

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