Submission #616658

#	Time	Username	Problem	Language	Result	Execution time	Memory
616658		AKaan37	Global Warming (CEOI18_glo)	C++17	100 / 100	880 ms	27548 KiB

glo

#include <bits/stdc++.h>
#define N 200005
using namespace std;
int t[N];
struct SegTree{
    vector<int> t;
    int n;
    SegTree(int sz){
        n = sz + 5;
        t.assign(4*n,0);
    }
    void clear(){
        t.assign(4*n,0);
    }
    void upd(int v,int tl,int tr,int pos,int val){
        if(tl == tr){
            t[v] = max(t[v],val);
            return;
        }
        int tm = (tl + tr)/2;
        if(pos <= tm)
            upd(v*2,tl,tm,pos,val);
        else upd(v*2+1,tm+1,tr,pos,val);
        t[v] = max(t[v*2],t[v*2+1]);
    }
    int get(int v,int tl,int tr,int l,int r){
        if(tr < l || r < tl)
            return 0;
        if(l <= tl && tr <= r){
            return t[v];
        }
        int tm = (tl + tr)/2;
        return max(get(v*2,tl,tm,l,r),get(v*2+1,tm+1,tr,l,r));
    }
    void upd(int pos,int val){
        upd(1,1,n,pos,val);
    }
    int get(int l,int r){
        return get(1,1,n,l,r);
    }
};
pair<int,int> sufquery[N];
pair<int,int> prequery[N];
void solve(){
    int n,x;
    cin >> n >> x;
    int best = 0;
    vector<int> compress;
    for(int i = 1;i<=n;i++){
        cin >> t[i];
        compress.push_back(t[i]);
        compress.push_back(t[i]+x);
        compress.push_back(t[i]-x);
    }
    sort(compress.begin(),compress.end());
    compress.resize(unique(compress.begin(),compress.end())-compress.begin());
    int sz = compress.size();
    SegTree tpre(sz);
    SegTree tsuf(sz);
    for(int i = 1;i<=n;i++){
        int num = upper_bound(compress.begin(),compress.end(),t[i] -x) - compress.begin();
        tpre.upd(num,tpre.get(1,num-1)+1);
        best = max(best,tpre.get(1,sz));
        sufquery[i+1] = {tpre.get(num,num),num};
    }
        //cout << best << endl;
    for(int i = n;i>=1;i--){
        int num = upper_bound(compress.begin(),compress.end(),t[i]+x) - compress.begin();
        tsuf.upd(num,tsuf.get(num+1,sz)+1);
        best = max(best,tsuf.get(1,sz));
        prequery[i-1] = {tsuf.get(num,num),num};
    }
    //cout << best << endl;
    tpre.clear();
    tsuf.clear();
    for(int i = 1;i<=n;i++){
        int num = upper_bound(compress.begin(),compress.end(),t[i]) - compress.begin();
        tpre.upd(num,tpre.get(1,num-1)+1);
        best = max(best,prequery[i].first + tpre.get(1,prequery[i].second-1));
    }
    for(int i = n;i>=1;i--){
        int num = upper_bound(compress.begin(),compress.end(),t[i]) - compress.begin();
        tsuf.upd(num,tsuf.get(num+1,sz)+1);
        best = max(best,sufquery[i].first + tsuf.get(sufquery[i].second+1,sz));
    }
    cout << best;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    #ifdef Local
        freopen("in.txt","r",stdin);
        freopen("out.txt","w",stdout);
    #endif
    int t = 1;
    //cin >> t;
    while(t--){
        solve();
    }
    #ifdef Local
        cout << endl << fixed << setprecision(2) << 1000.0*clock()/CLOCKS_PER_SEC << " milliseconds";
    #endif
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25