Submission #723618

#	Time	Username	Problem	Language	Result	Execution time	Memory
723618		drdilyor	Magic Tree (CEOI19_magictree)	C++17	34 / 100	2095 ms	1048576 KiB

magictree

#include<bits/stdc++.h>
 
using namespace std;
using ll = long long;
 
 
int main() {
    int n, m, k;
    cin >> n >> m >> k;
 
    vector<vector<int>> child(n);
    vector par(n, -1);
    for (int i = 1; i < n; i++) {
        cin >> par[i];
        child[--par[i]].push_back(i);
    }
 
    map<int,int> comp;
    vector<pair<int,int>> fruit(n);
    for (int i =0; i < m;i ++) {
        ll v, d, w;
        cin >> v >> d >> w;
        v--;
        comp[d] = 0;
        fruit[v] = {d, w};
    }

    k = 0;
    for (auto& mp: comp) mp.second = ++k;
    for (auto& [d, w] : fruit)
        d = comp[d];
 
    vector memo(n, vector(k+1, -1ll));
    auto dp = [&](auto& dp, int i, int day)->ll{
        if (day <= 0) return 0;
        if (memo[i][day] !=-1) return memo[i][day];
        ll res = 0ll;
        if (fruit[i].first == day) res += fruit[i].second;
        for (int e : child[i]) {
            res += dp(dp, e, day);
        }
        if (fruit[i].first) {
            if (day > fruit[i].first)
                res = max(res, dp(dp, i, fruit[i].first));
            else if (day == fruit[i].first)
                res = max(res, dp(dp, i, fruit[i].first-1));
        }
        return memo[i][day] = res;
    };
    cout << dp(dp, 0, k) << '\n';
    int bad = 0;
    for (int i = 0; i < n; i++) {
        for (int j = 1; j <= k; j++)
            bad += memo[i][j] == -1;
    }
    cerr << n*k - bad << ' ' << bad / double(n * k) << '\n';
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 3
• Subtask 3: 0 / 11
• Subtask 4: 12 / 12
• Subtask 5: 16 / 16
• Subtask 6: 0 / 13
• Subtask 7: 0 / 22
• Subtask 8: 0 / 17