Submission #1208837

#	Time	Username	Problem	Language	Result	Execution time	Memory
1208837		kitkat12	Cat Exercise (JOI23_ho_t4)	C++20	21 / 100	2094 ms	13232 KiB

Main

// Problem URL: https://oj.uz/problem/view/JOI23_ho_t4
// Start Time: 5/27/2025, 9:44:51 PM

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define mp make_pair
#define pb push_back
#define F first
#define S second
#define debug(x) std::cout << #x << ": " << x << "\n"
#define all(v) v.begin(), v.end()
#define li(i,a,b) for (int i = a; i < b; i++)
#define endl '\n'
#define mem(name,val) memset(name,val,sizeof(name))
#define max(a,b) max<ll>(a,b)
#define min(a,b) min<ll>(a,b)

const int nmax = 2e5+3;
vector<int> adj[nmax];
int p[nmax], pos[nmax];
int n;

bool obst[nmax]; // is there obstacle on node i 

ll maxmoves(int mn){ 
    if(obst[mn-1]==1 and obst[mn+1]==1)return 0; // base case
    // nadji ili p[mn]-1 ili max node pre blokade
    obst[mn]=1;

    // levo
    int l = mn;
    for(int i = mn-1; i>0 && obst[i]==0; i--){
        if(p[i]==p[mn]-1){
            l=i;break;
        }
        else if(l==mn || p[i]>p[l]) l=i;
    }

    // desno
    int r = mn;
    for(int i = mn+1; i < n+1 && obst[i]==0; i++){
        if(p[i]==p[mn]-1){
            r=i;break;
        }
        else if(r==mn || p[i]>p[r]) r=i;
    }

    ll left = 0, right = 0;
    if(l!=mn)
        left = abs<ll>(mn-l) + maxmoves(l);
    if(r!=mn)
        right = abs<ll>(r-mn)+ maxmoves(r);

    return max(left,right);
}

int main() 
{
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    cin>>n;
    li(i,1,n+1){
        cin>>p[i];
        pos[p[i]]=i;
    }
    li(i,0,n-1){
        int a,b;
        cin>>a>>b;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    obst[0]=obst[n+1]=1;

    cout<<maxmoves(pos[n]);

    return 0;
}

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