Submission #90924

#	Time	Username	Problem	Language	Result	Execution time	Memory
90924		toloraia	Gift (IZhO18_nicegift)	C++17	30 / 100	111 ms	20284 KiB

nicegift

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define F first
#define S second

using namespace std;

const ll N = 5e5 + 5, INF = 1e9 + 5;

ll n, k;
pair < ll, ll > P[N];
ll nn;
vector < ll > V[N], v;
ll S;

main()
{
    ios::sync_with_stdio(false);
    cin>>n>>k;
    for (ll i = 1; i <= n; i++){
        cin>>P[i].F;
        P[i].S = i;
        S += P[i].F;
    }
    sort (P + 1, P + n + 1);
    reverse (P + 1, P + n + 1);
    if (S <= 1e5){
        while (P[k].F > 0){
            ll I1 = k, I2 = k;
            for (ll i = 20; i >= 0; i--){
                if (I1 - (1<<i) <= 0)
                    continue;
                if (P[I1 - (1<<i)].F == P[k].F)
                    I1 -= (1<<i);
            }
            for (ll i = 20; i >= 0; i--){
                if (I2 + (1<<i) > n)
                    continue;
                if (P[I2 + (1<<i)].F == P[k].F)
                    I2 += (1<<i);
            }
            v.clear();
            for (ll i = 1; i < I1; i++){
                v.pb (P[i].S);
                P[i].F--;
            }
            for (ll i = I2; (ll)v.size() < k; i--){
                v.pb (P[i].S);
                P[i].F--;
            }
            V[++nn] = v;
        }
        if (P[1].F > 0){
            cout<<-1<<endl;
            return 0;
        }
        cout<<nn<<endl;
        for (ll i = 1; i <= nn; i++){
            cout<<"1 ";
            for (ll j = 0; j < k; j++)
                cout<<V[i][j]<<" ";
            cout<<endl;
        }
        return 0;
    }
    if (P[1].F == P[n].F){
        ll d = __gcd (n, k);
        ll m = k / d;
        if (P[1].F % m != 0){
            cout<<-1<<endl;
            return 0;
        }
        ll p = P[1].F / m;
        if (n * m > 3e6){
            cout<<-1<<endl;
            return 0;
        }
        cout<<n / d<<endl;
        for (ll i = 1; i <= n; i += d){
            cout<<p<<" ";
            for (ll j = i; j < i + d; j++)
                cout<<(j - 1) % n + 1<<" ";
            cout<<endl;
        }
        return 0;
    }
    return 0;
}

Compilation message (stderr)

nicegift.cpp:17:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main()
      ^

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