Submission #1114210

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114210		n3rm1n	Magic Tree (CEOI19_magictree)	C++17	37 / 100	87 ms	81992 KiB

magictree

#include<bits/stdc++.h>
//define endl '\n'
using namespace std;
const int MAXN = 2e5 + 10, MAXK = 22;
void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}
int n, m, k;
int p[MAXN];
long long v[MAXN], d[MAXN], w[MAXN];
vector < int > g[MAXN];
pair < int, int > f[MAXN];
long long leaf[MAXN], total = 0;
long long a[MAXN];
void read()
{
    cin >> n >> m >> k;
    for (int i = 1; i <= n; ++ i)
        leaf[i] = 1;
    for (int i = 2; i <= n; ++ i)
    {
        cin >> p[i];
        leaf[p[i]] = 0;
        g[p[i]].push_back(i);
    }
    bool no = 0;
    long long total = 0;
    vector < int > diffw;
    for (int i = 1; i <= m; ++ i)
    {
        cin >> v[i] >> d[i] >> w[i];
        a[v[i]] = d[i];
        if(!leaf[v[i]])no = 1;
        total += w[i];
        f[v[i]] = make_pair(d[i], w[i]);
    }

    if(!no)
    {
        cout << total << endl;
        exit(0);
    }
}

long long sub[MAXN][MAXK], dp[MAXN][MAXK], pref[MAXN][MAXK];
void dfs(int beg, int par)
{
    int dd = f[beg].first;
    if(dd)sub[beg][dd] += f[beg].second;
    long long sum = 0;
    for (auto nb: g[beg])
    {
        if(nb == par)continue;
        dfs(nb, beg);
        for (int i = 1; i <= k; ++ i)
            sub[beg][i] += sub[nb][i];
    }
    for (int day = 1; day <= k; ++ day)
    {
        long long cost = 0;
        if(day == dd)cost += f[beg].second;
        long long sum = 0;
        for (auto nb: g[beg])
            cost += max(pref[nb][day], sub[nb][day]);
        dp[beg][day] = max(dp[beg][day], cost);
        pref[beg][day] = max(dp[beg][day], pref[beg][day-1]);
    }
}
vector < int > vv;
void solve11()
{
    vv.push_back(0);
    for (int i = n; i >= 2; -- i)
    {
        int val = a[i];
        if(!val)continue;
        int sz = vv.size();
        if(vv[sz-1] <= val)vv.push_back(val);
        else
        {
            int l = 0, r = sz-1, mid, ans = -1;
            while(l <= r)
            {
                mid = (l + r)/2;
                if(vv[mid] <= val)l = mid + 1;
                else
                {
                    ans = mid;
                    r = mid - 1;
                }
            }
            assert(ans != -1);
            vv[mid] = val;
        }

    }
    cout << vv.size()-1 << endl;
}
int main()
{
    speed();

    read();

    if(k <= 20)
    {
        long long ans = 0;
        for (auto x: g[1])
        {
            dfs(x, 1);
            ans = ans + pref[x][k];
        }
        cout << ans << endl;
        return 0;
    }


   solve11();
    return 0;
}
/***
7 5 2
1 2 2 1 4 4
2 2 1
3 2 1
4 1 1
6 1 1
5 1 10

6 5 10
1 2 2 1 1
2 2 8
3 5 6
4 5 7
5 10 1
6 10 1

7 6 10
1 2 3 4 5 6
2 7 1
3 6 1
4 9 1
5 4 1
6 2 1
7 8 1



*/

Compilation message (stderr)

magictree.cpp: In function 'void dfs(int, int)':
magictree.cpp:65:19: warning: unused variable 'sum' [-Wunused-variable]
   65 |         long long sum = 0;
      |                   ^~~
magictree.cpp:53:15: warning: unused variable 'sum' [-Wunused-variable]
   53 |     long long sum = 0;
      |               ^~~

• Subtask 1: 6 / 6
• Subtask 2: 3 / 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