Submission #519786

#	Time	Username	Problem	Language	Result	Execution time	Memory
519786		Dasha_Gnedko	Gift (IZhO18_nicegift)	C++17	100 / 100	1591 ms	269492 KiB

nicegift

#include <bits/stdc++.h>

//#include <ext/pb_ds/detail/standard_policies.hpp>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//#pragma GCC optimize("Ofast")
//#pragma GCC target("avx2")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4")

using namespace std;

//using namespace __gnu_pbds;
//template <typename T> using ordered_set = tree <T, null_type, less < T >, rb_tree_tag, tree_order_statistics_node_update>;

mt19937 gen(time(0));

#define ll long long
#define ld long double
#define pb push_back
#define F first
#define S second
#define TIME clock() * 1.0 / CLOCKS_PER_SEC
#define sz(a) int32_t(a.size())
#define endl '\n'
//#define int long long

const int N = 4e6 + 100;
const int M = 18;
const int mod = 998244353;
const int inf = 1e9 + 7;

pair < ll, int > a[N];
set < pair < pair < int, int >, pair < ll, int > > > st;
vector < int > ans[N];
int nxt[1000100];

int get(int i)
{
    if (i == -1 || a[i].F) return i;
    return nxt[i] = get(nxt[i]);
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#else
//    freopen("input.txt", "r", stdin);
//    freopen("output.txt", "w", stdout);
#endif // LOCAL

    int n, k;
    cin >> n >> k;
    ll sum = 0, mx = 0;
    for(int i = 0; i < n; i++)
    {
        cin >> a[i].F;
        mx = max(mx, a[i].F);
        sum += a[i].F;
        a[i].S = i;
        nxt[i] = i + 1;
    }
    nxt[n - 1] = -1;
    if (sum % k || mx > sum / k)
    {
        cout << -1;
        return 0;
    }
    sort(a, a + n);
    reverse(a, a + n);
    int uk = 1;
    st.insert({{0, 0}, {sum / k, 0}});
    vector < pair < ll, int > > ve;
    while (sz(st))
    {
        pair < pair < int, int >, pair < ll, int > > p = *st.begin();
        st.erase(st.begin());
        int sz = p.F.F, i = get(p.F.S), numb = p.S.S; ll k = p.S.F;
        if (i == -1)
        {
            ve.pb({k, numb});
            continue;
        }
        if (a[i].F >= k)
        {
            a[i].F -= k;
            ans[numb].pb(a[i].S);
            st.insert({{sz + 1, i + 1}, {k, numb}});
            continue;
        }
        for(auto to: ans[numb])
            ans[uk].pb(to);
        ans[uk].pb(a[i].S);
        st.insert({{sz, i + 1}, {k - a[i].F, numb}});
        st.insert({{sz + 1, i + 1}, {a[i].F, uk}});
        a[i].F = 0;
        uk++;
    }
    cout << uk << endl;
    for(auto to: ve)
    {
        cout << to.F << " ";
        for(auto x: ans[to.S])
            cout << x + 1 << " ";
        cout << endl;
    }
}

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