Submission #723681

#	Time	Username	Problem	Language	Result	Execution time	Memory
723681		dxz05	Magic Tree (CEOI19_magictree)	C++17	34 / 100	1775 ms	792284 KiB

magictree

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
#define all(x) (x).begin(), (x).end()
#define MP make_pair
const int N = 100500;

struct fenwick{
    vector<int> f;
    fenwick(int n){
        f.resize(n + 2);
    };
    void add(int i, int x){
        i++;
        while (i < (int)f.size()){
            f[i] = max(f[i], x);
            i += (-i) & i;
        }
    }
    int get(int i){
        i++;
        int res = 0;
        while (i > 0){
            res = max(res, f[i]);
            i -= (-i) & i;
        }
        return res;
    }
};

vector<int> g[N];

vector<vector<ll>> dp;
pair<int, int> fruit[N];

void dfs(int v){
    dp[v][fruit[v].first] = fruit[v].second;

    for (int u : g[v]){
        dfs(u);
    }

    for (int t = 1; t < dp[v].size(); t++){
        for (int u : g[v]){
            dp[v][t] += dp[u][t];
        }
    }

    for (int t = 1; t < dp[v].size(); t++) dp[v][t] = max(dp[v][t], dp[v][t - 1]);

}

int LIS(const vector<int> &a){
    int n = (int) a.size();
    fenwick f(2e5);
    int res = 0;
    for (int i = 0; i < n; i++){
        int _dp = f.get(a[i]) + 1;
        f.add(a[i], _dp);
        res = max(res, _dp);
    }
    return res;
}

void solve(){
    int n, m, k;
    cin >> n >> m >> k;

    ll sum = 0;
    bool sub3 = true;
    for (int i = 1; i < n; i++){
        int p;
        cin >> p;
        --p;
        if (p != i - 1) sub3 = false;
        g[p].push_back(i);
    }

    map<int, int> mp;

    vector<int> a(n);
    for (int i = 0; i < m; i++){
        int v, d, w;
        cin >> v >> d >> w;
        --v;
        mp[d];
        fruit[v] = MP(d, w);
        sum += w;
        a[v] = d;
        if (w != 1) sub3 = false;
    }

    if (sub3){
        reverse(all(a));
        cout << LIS(a) << endl;
        return;
    }

    mp[0];
    k = 0;
    for (auto &now : mp){
        now.second = ++k;
    }

    for (int i = 0; i < n; i++){
        fruit[i].first = mp[fruit[i].first];
    }

    if (k > 1000){
        cout << sum << endl;
        return;
    }

    dp.assign(n, vector<ll>(k + 1, 0));

    dfs(0);

    cout << dp[0].back() << endl;

}

int main() {
    ios_base::sync_with_stdio(false);

#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif

    solve();

    return 0;
}

Compilation message (stderr)

magictree.cpp: In function 'void dfs(int)':
magictree.cpp:45:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |     for (int t = 1; t < dp[v].size(); t++){
      |                     ~~^~~~~~~~~~~~~~
magictree.cpp:51:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   51 |     for (int t = 1; t < dp[v].size(); t++) dp[v][t] = max(dp[v][t], dp[v][t - 1]);
      |                     ~~^~~~~~~~~~~~~~

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