Submission #519741

#	Time	Username	Problem	Language	Result	Execution time	Memory
519741		Monarchuwu	Magic Tree (CEOI19_magictree)	C++17	61 / 100	341 ms	702160 KiB

magictree

// nén cây và k dựa vào m
// O(n * min(m, k))
#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
typedef long long ll;

typedef pair<int, int> pii;
#define ff first
#define ss second

const int N = 1e5 + 9;
int n, m, k;
int p[N];
pii fruit[N];
vector<int> g[N];

namespace sub2 {
    bool check() {
        for (int i = 2; i <= n; ++i)
            if (g[i].size() && fruit[i].ff) return false;
        return true;
    }
    void solve() {
        ll sum(0);
        for (int i = 2; i <= n; ++i)
            sum += fruit[i].ss;
        cout << sum << '\n';
    }
}

namespace sub3 {
    bool check() {
        for (int i = 2; i <= n; ++i)
            if (p[i] != i - 1 || fruit[i].ss > 1) return false;
        return true;
    }
    int lis[N];
    void solve() {
        int cnt(0);
        for (int i = n, pos; i; --i) if (fruit[i].ff) {
            pos = upper_bound(lis + 1, lis + cnt + 1, fruit[i].ff) - lis;
            if (cnt < pos) cnt = pos;
            lis[pos] = fruit[i].ff;
        }
        cout << cnt << '\n';
    }
}

ll dp[N][1003];
namespace sub1456 {
    int cnt(0), b[N];
    void dfs(int u) {
        for (int v : g[u]) {
            dfs(v);
            for (int i = 1; i < cnt; ++i)
                dp[u][i] += dp[v][i];
        }
        if (fruit[u].ff) {
            dp[u][fruit[u].ff] += fruit[u].ss;
            for (int i = fruit[u].ff + 1; i < cnt; ++i)
                dp[u][i] = max(dp[u][i], dp[u][fruit[u].ff]);
        }
    }
    void solve() {
        for (int i = 1; i <= n; ++i) if (fruit[i].ff) b[++cnt] = fruit[i].ff;
        sort(b + 1, b + cnt + 1);
        cnt = unique(b + 1, b + cnt + 1) - b;
        for (int i = 1; i <= n; ++i)
            if (fruit[i].ff) fruit[i].ff = lower_bound(b + 1, b + cnt, fruit[i].ff) - b;

        dfs(1);
        cout << *max_element(dp[1], dp[1] + cnt) << '\n';
    }
}

int main() {
    cin.tie(NULL)->sync_with_stdio(false);
    cin >> n >> m >> k;
    for (int i = 2; i <= n; ++i) {
        cin >> p[i];
        g[p[i]].push_back(i);
    }
    for (int i = 0, v; i < m; ++i) {
        cin >> v;
        cin >> fruit[v].ff >> fruit[v].ss;
    }

    if (sub2::check()) sub2::solve();
    else if (sub3::check()) sub3::solve();
    else sub1456::solve();
}
/**  /\_/\
 *  (= ._.)
 *  / >0  \>1
**/

• 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: 0 / 22
• Subtask 8: 0 / 17