Submission #850971

#	Time	Username	Problem	Language	Result	Execution time	Memory
850971		wakandaaa	Gift (IZhO18_nicegift)	C++17	100 / 100	789 ms	97184 KiB

nicegift

#include <bits/stdc++.h>
#define int long long

using namespace std;

#define file ""

#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()

#define getbit(x, i) (((x) >> (i)) & 1)
#define bit(x) (1LL << (x))
#define popcount __builtin_popcountll

mt19937_64 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r) {
    return l + rd() % (r - l + 1);
}

const int N = 1e6 + 5;
const int mod = (int)1e9 + 7; // 998244353;
const int lg = 25; // lg + 1
const int oo = 1e9;
const long long ooo = 1e18;

template<class X, class Y> bool mini(X &a, Y b) {
    return a > b ? (a = b, true) : false;
}
template<class X, class Y> bool maxi(X &a, Y b) {
    return a < b ? (a = b, true) : false;
}
void add(int &a, int b) {
    a += b;
    if (a >= mod) a -= mod;
    if (a < 0) a += mod;
}

int n, k;
int a[N];
int s;

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);

    // freopen(file".inp", "r", stdin);
    // freopen(file".out", "w", stdout);

    cin >> n >> k;
    priority_queue<pair<int, int> > q;
    for (int i = 1; i <= n; ++i) {
    	cin >> a[i];
    	s += a[i];
    	q.emplace(a[i], i);
    }

    if (s % k != 0) {
    	cout << -1;
    	return 0;
    }

    if (q.top().fi > s / k) {
    	cout << -1;
    	return 0;
    }

    vector<vector<int> > res;

    while (s > 0) {
    	vector<int> id;
    	int rem = oo;
    	for (int i = 1; i <= k; ++i) {
    		id.push_back(q.top().se);
    		rem = q.top().fi;
    		q.pop();
    	}

    	if (q.size()) rem = min(rem, (s / k) - q.top().fi);
    	s -= k * rem;
    	vector<int> cur;
    	cur.push_back(rem);
    	for (int i : id) {
    		cur.push_back(i);
    		a[i] -= rem;
    		if (a[i] > 0) q.emplace(a[i], i);
    	}
    	res.push_back(cur);
    }

    cout << (int) res.size() << '\n';

    for (auto cur : res) {
    	for (int i : cur) cout << i << ' ';
    	cout << '\n';
    }

    return 0;
}

/*

*/

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