Submission #1167387

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167387		Syrius	Cat Exercise (JOI23_ho_t4)	C++20	41 / 100	166 ms	45664 KiB

Main

#include <bits/stdc++.h>
using namespace std;

#define int long long
#define ll long long
#define ff first
#define ss second
#define pint pair < int , int >
#define fast ios_base::sync_with_stdio(NULL); cin.tie(NULL)
typedef vector < int > vint;

const int inf = 1e18 + 9;
const int mxn = 2e5 + 2;
const int mod = 1e9 + 7;

int a[mxn];

struct node {

    int tl , tm , tr;
    int id;
    node *left , *right;    

    node (int l , int r) {
        tl = l , tr = r , tm = (l + r) / 2;
        if (tl == tr) {
            id = tl;
            return;
        }
        left = new node(tl , tm);
        right = new node(tm+1 , tr);
        id = (a[left->id] > a[right->id]) ? left->id : right->id;
    }

    int query(int l , int r) {
        if (tl == l && tr == r) return id;
        if (r <= tm) return left -> query(l , r);
        else if (l > tm) return right -> query(l , r);
        
        int idl = left -> query(l , tm);
        int idr = right -> query(tm+1 , r);
        return (a[idl] > a[idr]) ? idl : idr;
    }

} *root;

int dfs(int l , int r) {
    if (l == r) return 0;
    int x = root -> query(l , r);

    int t1 = -inf , t2 = -inf;
    if (x != r) t1 = root -> query(x+1 , r) - x + dfs(x+1 , r);
    if (x != l) t2 = x - root -> query(l , x-1) + dfs(l , x-1);

    return max(t1 , t2);
}

signed main() {

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

    for (int i = 0; i < n-1; i++) {
        int x , y;
        cin >> x >> y;
    }

    root = new node(1 , n);
    cout << dfs(1 , n) << '\n';
    return 0;
}

• Subtask 1: 7 / 7
• Subtask 2: 7 / 7
• Subtask 3: 7 / 7
• Subtask 4: 0 / 10
• Subtask 5: 20 / 20
• Subtask 6: 0 / 23
• Subtask 7: 0 / 26