Submission #1257874

#	Time	Username	Problem	Language	Result	Execution time	Memory
1257874		mariza	Bouquet (EGOI24_bouquet)	C++20	100 / 100	144 ms	28612 KiB

Main

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

typedef long long ll;
#define MID ((l+r)/2)

struct node{
    ll val;
    node *L, *R;

    void init(ll l, ll r){
        val=0;

        if(l!=r){
            L=new node;
            L->init(l,MID);

            R=new node;
            R->init(MID+1,r);
        }
    }

    void upd(ll l, ll r, ll i, ll x){
        if(l==i && i==r){
            val=max(val,x);
        }
        else if(l<=i && i<=r){
            L->upd(l,MID,i,x);
            R->upd(MID+1,r,i,x);

            val=max(L->val,R->val);
        }
    }

    ll ans(ll l, ll r, ll tl, ll tr){
        if(tr-tl+1<=0) return 0;
        else if(tl<=l && r<=tr) return val;
        else if(r<tl || tr<l) return 0;
        else return max(L->ans(l,MID,tl,tr),R->ans(MID+1,r,tl,tr));
    }
};

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    ll n;
    cin>>n;
    ll l[n], r[n];
    for(ll i=0; i<n; i++){
        cin>>l[i]>>r[i];
        l[i]=max(0ll,i-l[i]);
        r[i]=min(i+r[i],n-1);
    }

    ll ans[n]={};
    node seg; seg.init(0,n-1);
    vector<ll> xr[n]; 
    for(ll i=0; i<n; i++){
        xr[r[i]].push_back(i);
    }

    for(ll pos=n-1; pos>=0; pos--){
        for(auto i:xr[pos]){
            ans[i]=seg.ans(0,n-1,i+1,n-1)+1;
        }

        seg.upd(0,n-1,l[pos],ans[pos]);
    }

    ll max_ans=0;
    for(ll i=0; i<n; i++){
        max_ans=max(max_ans,ans[i]);
    }
    cout<<max_ans<<endl;
}

• Subtask 1: 8 / 8
• Subtask 2: 16 / 16
• Subtask 3: 28 / 28
• Subtask 4: 18 / 18
• Subtask 5: 30 / 30