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답안 #424703

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
424703 2021-06-12T09:17:07 Z blue Magic Tree (CEOI19_magictree) C++17
100 / 100
 265 ms 20656 KB 
#include <iostream>
#include <vector>
#include <set>
using namespace std;

/*
O(n*k):

Let dp[u][d] be the maximum amount of juice that can be collected if the edge (u, p[u]) is cut on day d.
Let DP[u][d] = max{d' <= d | dp[u][d']}

dp[u][d] = (d == fruit_day[u]) * fruit_weight[u]
           + sum{v in children[u] | DP[v][d]}

DP[u][d] = max(DP[u][d-1], dp[u][d])


O(n+k)
All the days d where DP[u][d] != DP[u][d-1] are the ripe days of some fruits in the subtree of u.

struct change
{
    int d;
    int changeDP;
}
*/

struct change
{
    int d;
    long long changeDP;
};

bool operator < (change A, change B)
{
    return A.d < B.d;
}

int main()
{
    int n, m, k;
    cin >> n >> m >> k;

    vector<int> children[n+1];
    for(int i = 2; i <= n; i++)
    {
        int p;
        cin >> p;
        children[p].push_back(i);
    }

    vector<int> fruit_day(n+1, 1);
    vector<long long> fruit_weight(n+1, 0);
    for(int f = 1; f <= m; f++)
    {
        int v, d, w;
        cin >> v >> d >> w;
        fruit_day[v] = d;
        fruit_weight[v] = w;
    }


    vector<int> subtree(n+1, 1);
    vector<int> maxchild(n+1, -1);

    for(int i = n; i >= 1; i--)
    {
        for(int v: children[i])
        {
            subtree[i] += subtree[v];

            if(maxchild[i] == -1 || subtree[v] > subtree[ maxchild[i] ])
                maxchild[i] = v;
        }
    }


    set<change>* DP[n+1];
    for(int i = 1; i <= n; i++)
    {
        DP[i] = new set<change>;
    }

    for(int u = n; u >= 1; u--)
    {
        // cerr << "u = " << u << '\n';
        if(children[u].size() == 0)
        {
            DP[u]->insert(change{fruit_day[u], +fruit_weight[u]});
        }
        else
        {
            DP[u] = DP[ maxchild[u] ];
            for(int v: children[u])
            {
                if(v == maxchild[u]) continue;
                for(change d: *DP[v])
                {
                    set<change>::iterator X = DP[u]->find(d);
                    if(X == DP[u]->end())
                    {
                        DP[u]->insert(d);
                    }
                    else
                    {
                        change x = *X;
                        DP[u]->erase(x);
                        x.changeDP += d.changeDP;
                        DP[u]->insert(x);
                    }
                }
                DP[v]->clear();
            }

            //Update with fruit(u)
            long long current_fruit_val = fruit_weight[u];
            while(1)
            {
                // cerr << "cfv = " << current_fruit_val << '\n';
                if(current_fruit_val == 0) break;
                set<change>::iterator it = DP[u]->upper_bound(change{fruit_day[u], fruit_weight[u]});

                // if(it == DP[u]->end()) cerr << "it = end\n";
                // else cerr << "it = " << it->d << ' ' << it->changeDP << '\n';

                if(it == DP[u]->end()) break;
                else if(it->changeDP <= current_fruit_val)
                {
                    current_fruit_val -= it->changeDP;
                    DP[u]->erase(it);
                }
                else
                {
                    change X = *it;
                    DP[u]->erase(X);
                    X.changeDP -= current_fruit_val;
                    current_fruit_val = 0;
                    DP[u]->insert(X);
                }
            }

            set<change>::iterator it = DP[u]->find(change{fruit_day[u], +fruit_weight[u]});
            if(it == DP[u]->end())
            {
                DP[u]->insert(change{fruit_day[u], +fruit_weight[u]});
            }
            else
            {
                change x = *it;
                DP[u]->erase(x);
                x.changeDP += +fruit_weight[u];
                DP[u]->insert(x);
            }
        }

        // for(change c:*DP[u]) cerr << c.d << ' ' << c.changeDP << '\n';

    }

    long long res = 0;
    for(change c: *DP[1]) res += c.changeDP;

    cout << res << '\n';
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct

Subtask #2
3.0 / 3.0

# 결과 실행 시간 메모리 Grader output
1 Correct 148 ms 16888 KB Output is correct
2 Correct 93 ms 16880 KB Output is correct
3 Correct 265 ms 20656 KB Output is correct
4 Correct 173 ms 20280 KB Output is correct
5 Correct 215 ms 20388 KB Output is correct

Subtask #3
11.0 / 11.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 2 ms 332 KB Output is correct
3 Correct 2 ms 460 KB Output is correct
4 Correct 136 ms 16704 KB Output is correct
5 Correct 179 ms 20612 KB Output is correct
6 Correct 149 ms 16708 KB Output is correct

Subtask #4
12.0 / 12.0

# 결과 실행 시간 메모리 Grader output
1 Correct 183 ms 16404 KB Output is correct
2 Correct 162 ms 15992 KB Output is correct
3 Correct 168 ms 14992 KB Output is correct
4 Correct 131 ms 18744 KB Output is correct
5 Correct 142 ms 15172 KB Output is correct

Subtask #5
16.0 / 16.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 169 ms 17528 KB Output is correct
11 Correct 157 ms 17092 KB Output is correct
12 Correct 147 ms 14948 KB Output is correct
13 Correct 115 ms 18668 KB Output is correct
14 Correct 142 ms 15320 KB Output is correct

Subtask #6
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 16 ms 3376 KB Output is correct
2 Correct 81 ms 16224 KB Output is correct
3 Correct 75 ms 16068 KB Output is correct
4 Correct 80 ms 16244 KB Output is correct
5 Correct 47 ms 18420 KB Output is correct
6 Correct 85 ms 14940 KB Output is correct
7 Correct 66 ms 15084 KB Output is correct

Subtask #7
22.0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 2 ms 332 KB Output is correct
12 Correct 2 ms 460 KB Output is correct
13 Correct 136 ms 16704 KB Output is correct
14 Correct 179 ms 20612 KB Output is correct
15 Correct 149 ms 16708 KB Output is correct
16 Correct 169 ms 17528 KB Output is correct
17 Correct 157 ms 17092 KB Output is correct
18 Correct 147 ms 14948 KB Output is correct
19 Correct 115 ms 18668 KB Output is correct
20 Correct 142 ms 15320 KB Output is correct
21 Correct 34 ms 3948 KB Output is correct
22 Correct 159 ms 17732 KB Output is correct
23 Correct 179 ms 17812 KB Output is correct
24 Correct 219 ms 19164 KB Output is correct
25 Correct 147 ms 19680 KB Output is correct
26 Correct 232 ms 18692 KB Output is correct
27 Correct 167 ms 17448 KB Output is correct

Subtask #8
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 1 ms 332 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 204 KB Output is correct
10 Correct 148 ms 16888 KB Output is correct
11 Correct 93 ms 16880 KB Output is correct
12 Correct 265 ms 20656 KB Output is correct
13 Correct 173 ms 20280 KB Output is correct
14 Correct 215 ms 20388 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 2 ms 332 KB Output is correct
17 Correct 2 ms 460 KB Output is correct
18 Correct 136 ms 16704 KB Output is correct
19 Correct 179 ms 20612 KB Output is correct
20 Correct 149 ms 16708 KB Output is correct
21 Correct 183 ms 16404 KB Output is correct
22 Correct 162 ms 15992 KB Output is correct
23 Correct 168 ms 14992 KB Output is correct
24 Correct 131 ms 18744 KB Output is correct
25 Correct 142 ms 15172 KB Output is correct
26 Correct 169 ms 17528 KB Output is correct
27 Correct 157 ms 17092 KB Output is correct
28 Correct 147 ms 14948 KB Output is correct
29 Correct 115 ms 18668 KB Output is correct
30 Correct 142 ms 15320 KB Output is correct
31 Correct 16 ms 3376 KB Output is correct
32 Correct 81 ms 16224 KB Output is correct
33 Correct 75 ms 16068 KB Output is correct
34 Correct 80 ms 16244 KB Output is correct
35 Correct 47 ms 18420 KB Output is correct
36 Correct 85 ms 14940 KB Output is correct
37 Correct 66 ms 15084 KB Output is correct
38 Correct 34 ms 3948 KB Output is correct
39 Correct 159 ms 17732 KB Output is correct
40 Correct 179 ms 17812 KB Output is correct
41 Correct 219 ms 19164 KB Output is correct
42 Correct 147 ms 19680 KB Output is correct
43 Correct 232 ms 18692 KB Output is correct
44 Correct 167 ms 17448 KB Output is correct
45 Correct 44 ms 4256 KB Output is correct
46 Correct 157 ms 18364 KB Output is correct
47 Correct 172 ms 18376 KB Output is correct
48 Correct 249 ms 20388 KB Output is correct
49 Correct 204 ms 20404 KB Output is correct
50 Correct 265 ms 19652 KB Output is correct
51 Correct 226 ms 18324 KB Output is correct