Submission #943944

#	Time	Username	Problem	Language	Result	Execution time	Memory
943944		kim	Fireworks (APIO16_fireworks)	C++17	55 / 100	2027 ms	41300 KiB

fireworks

#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
using ll=long long;

struct A{
    multiset<ll> L,R;
    ll mn;
    A():mn(0){}
    void insert(ll x){
        if(L.empty()) L.emplace(x), R.emplace(x);
        else if(x<*L.rbegin()){
            mn+=*L.rbegin()-x;
            L.emplace(x), L.emplace(x);
            R.emplace(*L.rbegin()), L.erase(prev(L.end()));
        }
        else if(x>*R.begin()){
            mn+=x-*R.begin();
            R.emplace(x), R.emplace(x);
            L.emplace(*R.begin()), R.erase(R.begin());
        }
        else L.emplace(x), R.emplace(x);
    }
    A& operator+=(A o){
        if(L.size()<o.L.size()) swap(*this,o);
        
        for(auto &e:o.L){
            if(e<*R.begin()) L.emplace(e); 
            else{
                mn+=e-*R.begin();
                R.emplace(e), L.emplace(*R.begin()), R.erase(R.begin());
            }
        }
        for(auto &e:o.R){
            if(e>*L.rbegin()) R.emplace(e); 
            else{
                mn+=*L.rbegin()-e;
                L.emplace(e), R.emplace(*L.rbegin()), L.erase(prev(L.end()));
            }
        }
        mn+=o.mn;

        return *this;
    }
    void clear(){
        L.clear(),R.clear();
    }
}t[300005];

int p[300005];
ll c[300005];

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

    int n,m; cin>>n>>m;
    for(int i=2;i<=n+m;++i) cin>>p[i]>>c[i];
    for(int i=n+m;i>n;--i) t[p[i]].insert(c[i]);
    for(int i=n;i>1;--i){
        while(t[i].R.size()>1){
            auto itr=prev(t[i].R.end());
            t[i].R.erase(itr);
        }
        auto itr1=prev(t[i].L.end()), itr2=t[i].R.begin();
        t[i].L.emplace(*itr1+c[i]), t[i].L.erase(itr1);
        t[i].R.emplace(*itr2+c[i]), t[i].R.erase(itr2);
        t[p[i]]+=t[i];
        t[i].clear();
    }
    cout<<t[1].mn;

}

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 29 / 29
• Subtask 4: 0 / 45