oj.uz

Submission #769231

# Submission time Handle Problem Language Result Execution time Memory
769231 2023-06-29T10:18:43 Z danikoynov Cat Exercise (JOI23_ho_t4) C++14
31 / 100
 220 ms 19528 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], dp[maxn], pos[maxn];
vector < int > adj[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], 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], 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(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], 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] + v - lf.second);
            }
            if (rf.first != -1)
                dp[v] = max(dp[v], dp[rf.second] + rf.second - v);
            //cout << dp[v] << endl;
        }
        cout << dp[pos[n]] << endl;
    }



}

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

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct

Subtask #2
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 4 ms 4948 KB Output is correct
13 Correct 6 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct

Subtask #3
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 4 ms 4948 KB Output is correct
13 Correct 6 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 104 ms 5596 KB Output is correct
19 Correct 87 ms 5640 KB Output is correct
20 Correct 88 ms 5568 KB Output is correct
21 Correct 7 ms 5628 KB Output is correct
22 Correct 6 ms 5412 KB Output is correct
23 Correct 7 ms 5504 KB Output is correct
24 Correct 6 ms 5408 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 4 ms 4948 KB Output is correct
13 Correct 6 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 104 ms 5596 KB Output is correct
19 Correct 87 ms 5640 KB Output is correct
20 Correct 88 ms 5568 KB Output is correct
21 Correct 7 ms 5628 KB Output is correct
22 Correct 6 ms 5412 KB Output is correct
23 Correct 7 ms 5504 KB Output is correct
24 Correct 6 ms 5408 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 88 ms 5548 KB Output is correct
27 Correct 86 ms 5452 KB Output is correct
28 Correct 86 ms 5596 KB Output is correct
29 Correct 99 ms 5484 KB Output is correct
30 Correct 12 ms 5204 KB Output is correct
31 Correct 16 ms 5312 KB Output is correct
32 Correct 14 ms 5316 KB Output is correct
33 Correct 18 ms 5344 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 4 ms 4948 KB Output is correct
13 Correct 6 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 104 ms 5596 KB Output is correct
19 Correct 87 ms 5640 KB Output is correct
20 Correct 88 ms 5568 KB Output is correct
21 Correct 7 ms 5628 KB Output is correct
22 Correct 6 ms 5412 KB Output is correct
23 Correct 7 ms 5504 KB Output is correct
24 Correct 6 ms 5408 KB Output is correct
25 Incorrect 219 ms 19528 KB Output isn't correct
26 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Incorrect 220 ms 19284 KB Output isn't correct
4 Halted 0 ms 0 KB -

Subtask #7
0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 3 ms 5012 KB Output is correct
4 Correct 2 ms 5016 KB Output is correct
5 Correct 4 ms 4972 KB Output is correct
6 Correct 3 ms 5012 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 3 ms 5016 KB Output is correct
9 Correct 3 ms 5016 KB Output is correct
10 Correct 3 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 4 ms 4948 KB Output is correct
13 Correct 6 ms 4948 KB Output is correct
14 Correct 3 ms 4948 KB Output is correct
15 Correct 3 ms 5016 KB Output is correct
16 Correct 3 ms 4948 KB Output is correct
17 Correct 3 ms 4948 KB Output is correct
18 Correct 104 ms 5596 KB Output is correct
19 Correct 87 ms 5640 KB Output is correct
20 Correct 88 ms 5568 KB Output is correct
21 Correct 7 ms 5628 KB Output is correct
22 Correct 6 ms 5412 KB Output is correct
23 Correct 7 ms 5504 KB Output is correct
24 Correct 6 ms 5408 KB Output is correct
25 Correct 3 ms 4948 KB Output is correct
26 Correct 88 ms 5548 KB Output is correct
27 Correct 86 ms 5452 KB Output is correct
28 Correct 86 ms 5596 KB Output is correct
29 Correct 99 ms 5484 KB Output is correct
30 Correct 12 ms 5204 KB Output is correct
31 Correct 16 ms 5312 KB Output is correct
32 Correct 14 ms 5316 KB Output is correct
33 Correct 18 ms 5344 KB Output is correct
34 Incorrect 219 ms 19528 KB Output isn't correct
35 Halted 0 ms 0 KB -