Submission #810673

#	Time	Username	Problem	Language	Result	Execution time	Memory
810673		GrindMachine	Magic Tree (CEOI19_magictree)	C++17	100 / 100	847 ms	136068 KiB

magictree

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct fenwick {
    int siz;
    map<int,T> tree;

    fenwick(){

    }

    int lsb(int x) {
        return x & -x;
    }

    void pupd(int i, T v) {
        while (i < N) {
            tree[i] += v;
            i += lsb(i);
        }
    }

    T sum(int i) {
        T res = 0;

        while (i) {
            if(tree.find(i) != tree.end()){
                res += tree[i];
            }
            i -= lsb(i);
        }

        return res;
    }

    T query(int l, int r) {
        if (l > r) return 0;
        T res = sum(r) - sum(l - 1);
        return res;
    }
};

vector<ll> adj[N];
vector<pll> here(N,{-1,-1});
fenwick<ll> fenw[N];
set<ll> days[N];
vector<ll> subsiz(N);

void dfs1(ll u){
    subsiz[u] = (here[u].ff != -1);
    trav(v,adj[u]){
        dfs1(v);
        subsiz[u] += subsiz[v];
    }
}

void dfs2(ll u){
    ll mx = -1, largest = -1;
    trav(v,adj[u]){
        if(subsiz[v] > mx){
            mx = subsiz[v];
            largest = v;
        }
    }

    if(largest != -1){
        dfs2(largest);
        swap(days[u],days[largest]);
        swap(fenw[u],fenw[largest]);
    }

    auto [day,cost] = here[u];
    if(day != -1){
        days[u].insert(day);
        if(largest != -1){
            cost += fenw[u].query(1,day);
        }
    }

    trav(v,adj[u]){
        if(v == largest) conts;
        dfs2(v);

        if(day != -1){
            cost += fenw[v].query(1,day);
        }

        trav(d,days[v]){
            ll val = fenw[v].query(d,d);
            fenw[u].pupd(d,val);
            days[u].insert(d);
        }

        days[v].clear();
    }

    if(day != -1){
        ll val = fenw[u].query(1,day);

        if(cost > val){
            fenw[u].pupd(day,cost-val);

            auto it = days[u].find(day);
            it++;
            
            vector<ll> toerase;

            for(; it != days[u].end(); ++it){
                ll p = *it;
                ll add = fenw[u].query(p,p);
                val += add;
                if(val > cost){
                    fenw[u].pupd(p,-add+val-cost);
                    break;
                }
                else{
                    fenw[u].pupd(p,-add);
                    toerase.pb(p);
                }
            }

            trav(p,toerase){
                days[u].erase(p);
            }
        }
    }
}

void solve(int test_case)
{
    ll n,m,k; cin >> n >> m >> k;
    for(int i = 2; i <= n; ++i){
        ll p; cin >> p;
        adj[p].pb(i);
    } 

    vector<ll> days;

    rep1(i,m){
        ll u,d,w; cin >> u >> d >> w;
        days.pb(d);
        here[u] = {d,w};
    }

    sort(all(days));
    days.resize(unique(all(days))-days.begin());

    rep1(i,n){
        if(here[i].ff != -1){
            here[i].ff = lower_bound(all(days),here[i].ff)-days.begin()+1;
        }
    }

    dfs1(1);
    dfs2(1);

    ll ans = fenw[1].query(1,N-1);
    cout << ans << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 3 / 3
• Subtask 3: 11 / 11
• Subtask 4: 12 / 12
• Subtask 5: 16 / 16
• Subtask 6: 13 / 13
• Subtask 7: 22 / 22
• Subtask 8: 17 / 17