Submission #1064945

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064945		Boomyday	Jobs (BOI24_jobs)	C++17	43 / 100	2109 ms	1019004 KiB

Main

//
// Created by adavy on 8/18/2024.
//
#include <bits/stdc++.h>
//#pragma GCC optimize("O3")

using namespace std;

using ll = long long;
const ll MOD = 1e9 + 7;

#define int ll

#define f first
#define s second

pair<ll,ll> merge(pair<ll,ll> a, pair<ll,ll> b){
    return {min(a.f,b.f),a.s-max(a.f,b.f)+b.s};
}


struct prs{
    set<pair<ll,ll>> ps;
    void insert(pair<ll,ll> p){

        //cout << "ps: " << endl;
        //for(auto& itm:ps){
        //    cout << itm.f << " " << itm.s << endl;
        //}
        //cout << "p: " << p.f << " " << p.s << endl;
        while(1){
            auto it = ps.lower_bound(p);
            if (it != ps.end()) {
                if (it-> f <= p.s){
                    p = merge(p,*it);
                    ps.erase(it);
                    continue;
                }
            }
            auto it2 = ps.upper_bound(p);
            if (it2 != ps.begin()){
                --it2;
                if (it2->s >= p.f){
                    p = merge(p,*it2);
                    ps.erase(it2);
                    continue;
                }
            }

            ps.insert(p);

            break;
        }
    }
    void subtract(ll x){

        ll balance = -x;
        ll neg = balance;
        while (!ps.empty() && balance < 0){


            balance -= ps.begin()->f;
            neg = min(neg,balance);
            balance += ps.begin()->s;
            ps.erase(ps.begin());

        }
        if (balance >= 0){
            ps.insert({-neg,balance-neg});
        }
    }
};


vector<int> val;
vector<prs> sets;
vector<int> which;

vector<vector<int>> adj;


void iterative_dfs(int rt){
    stack<pair<pair<int,int>,bool>> st;
    st.push({{rt,-1},false});
    while (!st.empty()){
        auto [nds,stt] = st.top(); st.pop();
        int v = nds.f, p = nds.s;
        //if (v%1000 == 0) cout << "v: " << v << " p: " << p << " stt: " << stt << endl;
        if (stt==0){
            st.push({{v,p},true});
            for(int u:adj[v]){
                if (u == p) continue;
                st.push({{u,v},false});
            }
        }
        else{
            int maxsz = -1, maxch = -1;
            for(int u:adj[v]){
                if (u == p) continue;
                if (sets[u].ps.size() > maxsz){
                    maxsz = sets[u].ps.size();
                    maxch = u;
                }
            }


            if (maxsz == -1){
                which[v] = v;
            }
            else {
                which[v] = which[maxch];
            }
            for(int u:adj[v]){

                if (u==p || u == maxch) continue;
                for(auto& itm:sets[u].ps){
                    sets[which[v]].insert(itm);
                }
            }

            if (val[v] > 0){
                sets[which[v]].insert({0LL,val[v]});
            }
            else {
                sets[which[v]].subtract(-val[v]);

            }
        }
    }

}

signed main(){
    //freopen("input.txt","r",stdin);
    std::ios::sync_with_stdio(false); cin.tie(NULL);
    int N,s; cin >> N >> s;
    adj.resize(N+5);

    val.resize(N+1);
    sets.resize(N+1);
    which.resize(N+1,-1);
    val[0] = 0;
    for(int i=1;i<=N;++i){
        ll x,p; cin >> x >> p;
        val[i] = x;
        adj[p].push_back(i);
        adj[i].push_back(p);
    }
    iterative_dfs(0);
    int t = s;



    for(auto& item:sets[which[0]].ps){
        if (t >= item.f){
            t -= item.f;
            t += item.s;
        }
    }
    cout << t-s << endl;





}

Compilation message (stderr)

Main.cpp: In function 'void iterative_dfs(ll)':
Main.cpp:100:39: warning: comparison of integer expressions of different signedness: 'std::set<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
  100 |                 if (sets[u].ps.size() > maxsz){
      |                     ~~~~~~~~~~~~~~~~~~^~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 14 / 14
• Subtask 3: 0 / 15
• Subtask 4: 29 / 29
• Subtask 5: 0 / 31