Submission #378842

#	Time	Username	Problem	Language	Result	Execution time	Memory
378842		wiwiho	Gift (IZhO18_nicegift)	C++14	7 / 100	429 ms	61880 KiB

nicegift

#include <bits/stdc++.h>

#define mp make_pair
#define F first
#define S second
#define eb emplace_back
#define printv(a, b) { \
    for(auto pv : a) b << pv << " "; \
    b << "\n"; \
}

using namespace std;

typedef long long ll;

using pll = pair<ll, ll>;
using pii = pair<int, int>;

const ll MAX = 1LL << 60;

ostream& operator<<(ostream& o, pll p){
    return o << '(' << p.F << ',' << p.S << ')';
}

ll iceil(ll a, ll b){
    return (a + b - 1) / b;
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    
    ll n, k;
    cin >> n >> k;

    vector<pll> a(n);
    for(int i = 0; i < n; i++){
        cin >> a[i].F;
        a[i].S = i + 1;
    }
    sort(a.begin(), a.end(), greater<>());

    vector<pair<ll, vector<int>>> ans;
    int lst = 0;
    for(int i = 1; i < n; i++){
        while(a[lst].F == 0) lst++;
        if(i == lst) continue;
        ll t = min(a[i].F, a[lst].F);
        a[lst].F -= t;
        a[i].F  -= t;
        ans.eb(mp(t, vector<int>()));
        ans.back().S.eb(a[lst].S);
        ans.back().S.eb(a[i].S);
    }

    for(int i = 0; i < n; i++){
        if(a[i].F != 0){
            cout << "-1\n";
            return 0;
        }
    }

    cout << ans.size() << "\n";
    for(auto& i : ans){
        cout << i.F << " ";
        printv(i.S, cout);
    }

    return 0;
}

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