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Submission #769236

# Submission time Handle Problem Language Result Execution time Memory
769236 2023-06-29T10:21:39 Z danikoynov Cat Exercise (JOI23_ho_t4) C++14
51 / 100
 296 ms 24144 KB 
#include<bits/stdc++.h>
#define endl '\n'

using namespace std;
typedef long long ll;

void speed()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
}

const int maxn = 2e5 + 10;

int n, a[maxn], used[maxn], pos[maxn];
vector < int > adj[maxn];
ll dp[maxn];
int rec(int val)
{
    if (used[val])
        return dp[val];
    used[val] = 1;
    int left = 0, right = n + 1;
    for (int i = n; i > val; i --)
    {
        if (pos[i] > pos[val])
        {
            right = min(right, pos[i]);
        }
        else
        {
            left = max(left, pos[i]);
        }
    }

    int mx = -1;
    for (int i = pos[val] + 1; i < right; i ++)
    {
        if (a[i] > mx)
        {
            mx = a[i];
            dp[val] = max(dp[val], (ll)(i - pos[val] + rec(a[i])));
        }
    }
    mx = -1;
    for (int i = pos[val] - 1; i > left; i --)
    {
        if (a[i] > mx)
        {
            mx = a[i];
            dp[val] = max(dp[val], (ll)(pos[val] - i + rec(a[i])));
        }
    }
    return dp[val];
}

int dfs(int v, int p, int mx, int dis, int val)
{
    if (mx > val)
        return 0;

    int ans = 0;
    if (a[v] == mx)
        ans = max((ll)ans, dis + dp[v]);

    for (int u : adj[v])
    {
        if (u == p)
            continue;
        ans = max(ans, dfs(u, v, max(mx, a[u]), dis + 1, val));

    }

    return ans;
}

int bef[maxn], aft[maxn];

pair < int, int > tree[4 * maxn];

void build_tree(int root, int left, int right)
{
    if (left == right)
    {
        tree[root] = {a[left], left};
        return;
    }

    int mid = (left + right) / 2;
    build_tree(root * 2, left, mid);
    build_tree(root * 2 + 1, mid + 1, right);

    tree[root] = max(tree[root * 2], tree[root * 2 + 1]);
}

pair < int, int > query(int root, int left, int right, int qleft, int qright)
{
    if (left > qright || right < qleft)
        return {-1, -1};

    if (left >= qleft && right <= qright)
        return tree[root];

    int mid = (left + right) / 2;
    return max(query(root * 2, left, mid, qleft, qright),
               query(root * 2 + 1, mid + 1, right, qleft, qright));
}

void solve()
{
    cin >> n;
    for (int i = 1; i <= n; i ++)
    {
        cin >> a[i];
        pos[a[i]] = i;
    }


    for (int i = 1; i < n; i ++)
    {
        int v, u;
        cin >> v >> u;
        adj[v].push_back(u);
        adj[u].push_back(v);
    }


    if (n <= 5000)
    {
        for (int i = 1; i <= n; i ++)
        {
            int v = pos[i];
            for (int u : adj[v])
            {
                dp[v] = max(dp[v], (ll)dfs(u, v, a[u], 1, a[v]));
            }
            ///cout << v << " : " << dp[v] << endl;
        }


        cout << dp[pos[n]] << endl;
    }
    else
    {
        stack < int > st;
        for (int i = 1; i <= n; i ++)
        {
            while(!st.empty() && a[st.top()] < a[i])
                st.pop();

            if (!st.empty())
                bef[i] = st.top();
            ///cout << "stack " << i << " " << st.top() << endl;
            st.push(i);
        }

        while(!st.empty())
            st.pop();

        for (int i = n; i > 0; i --)
        {
            while(!st.empty() && a[st.top()] < a[i])
                st.pop();
            if (!st.empty())
                aft[i] = st.top();
            else
                aft[i] = n + 1;
            st.push(i);
        }
        build_tree(1, 1, n);
        for (int i = 1; i <= n; i ++)
        {
            int v = pos[i];
            ///cout << "now " << v << " " << bef[v] << " " <<aft[v] << endl;
            pair < int, int > lf = query(1, 1, n, bef[v] + 1, v - 1);
            pair < int, int > rf = query(1, 1, n, v + 1, aft[v] - 1);
            ///cout << v << " " << lf.second << " " << rf.second << endl;
            if (lf.first != -1)
            {
                ///cout << "here " << dp[lf.first] << " " << lf.first << endl;
                dp[v] = max(dp[v], dp[lf.second] + (ll)(v - lf.second));
            }
            if (rf.first != -1)
                dp[v] = max(dp[v], dp[rf.second] + (ll)(rf.second - v));
            //cout << dp[v] << endl;
        }
        cout << dp[pos[n]] << endl;
    }



}

int main()
{
    solve();
    return 0;
}
/**
5
5 3 2 1 4
1 2
2 3
3 4
4 5
*/

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 4 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 4 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 92 ms 5552 KB Output is correct
19 Correct 83 ms 5544 KB Output is correct
20 Correct 88 ms 5612 KB Output is correct
21 Correct 8 ms 5520 KB Output is correct
22 Correct 6 ms 5460 KB Output is correct
23 Correct 8 ms 5460 KB Output is correct
24 Correct 9 ms 5460 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 4 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 92 ms 5552 KB Output is correct
19 Correct 83 ms 5544 KB Output is correct
20 Correct 88 ms 5612 KB Output is correct
21 Correct 8 ms 5520 KB Output is correct
22 Correct 6 ms 5460 KB Output is correct
23 Correct 8 ms 5460 KB Output is correct
24 Correct 9 ms 5460 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 90 ms 5412 KB Output is correct
27 Correct 96 ms 5432 KB Output is correct
28 Correct 87 ms 5524 KB Output is correct
29 Correct 85 ms 5544 KB Output is correct
30 Correct 11 ms 5256 KB Output is correct
31 Correct 15 ms 5264 KB Output is correct
32 Correct 12 ms 5264 KB Output is correct
33 Correct 17 ms 5204 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 4 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 92 ms 5552 KB Output is correct
19 Correct 83 ms 5544 KB Output is correct
20 Correct 88 ms 5612 KB Output is correct
21 Correct 8 ms 5520 KB Output is correct
22 Correct 6 ms 5460 KB Output is correct
23 Correct 8 ms 5460 KB Output is correct
24 Correct 9 ms 5460 KB Output is correct
25 Correct 236 ms 20412 KB Output is correct
26 Correct 258 ms 24144 KB Output is correct
27 Correct 254 ms 24140 KB Output is correct
28 Correct 251 ms 23792 KB Output is correct
29 Correct 256 ms 23572 KB Output is correct
30 Correct 241 ms 23712 KB Output is correct
31 Correct 296 ms 23828 KB Output is correct

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Incorrect 244 ms 20108 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #7
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 2 ms 4948 KB Output is correct
6 Correct 2 ms 5016 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 4 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 3 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 4 ms 4948 KB Output is correct
18 Correct 92 ms 5552 KB Output is correct
19 Correct 83 ms 5544 KB Output is correct
20 Correct 88 ms 5612 KB Output is correct
21 Correct 8 ms 5520 KB Output is correct
22 Correct 6 ms 5460 KB Output is correct
23 Correct 8 ms 5460 KB Output is correct
24 Correct 9 ms 5460 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 90 ms 5412 KB Output is correct
27 Correct 96 ms 5432 KB Output is correct
28 Correct 87 ms 5524 KB Output is correct
29 Correct 85 ms 5544 KB Output is correct
30 Correct 11 ms 5256 KB Output is correct
31 Correct 15 ms 5264 KB Output is correct
32 Correct 12 ms 5264 KB Output is correct
33 Correct 17 ms 5204 KB Output is correct
34 Correct 236 ms 20412 KB Output is correct
35 Correct 258 ms 24144 KB Output is correct
36 Correct 254 ms 24140 KB Output is correct
37 Correct 251 ms 23792 KB Output is correct
38 Correct 256 ms 23572 KB Output is correct
39 Correct 241 ms 23712 KB Output is correct
40 Correct 296 ms 23828 KB Output is correct
41 Correct 2 ms 4948 KB Output is correct
42 Correct 2 ms 4948 KB Output is correct
43 Incorrect 244 ms 20108 KB Output isn't correct
44 Halted 0 ms 0 KB -