Submission #1182271

#	Time	Username	Problem	Language	Result	Execution time	Memory
1182271		cpdreamer	Global Warming (CEOI18_glo)	C++20	100 / 100	360 ms	28028 KiB

glo

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define P pair
#define F first
#define all(v) v.begin(),v.end()
#define V vector
#define pb push_back
#define S second
void file() {
    freopen("input.txt.txt", "r", stdin);
    freopen("output.txt.txt", "w", stdout);
}
const ll MOD=(ll)1e9+7;
struct segtree{
private:
    struct node{
        int maxd;
    };
    node single(int v){
        return {v};
    }
    node neutral={0};
    node merge(node a,node b){
        return {max(a.maxd,b.maxd)};
    }
public:
    int size;
    V<node>query;
    void init(int n){
        size=1;
        while(size<n)size*=2;
        query.assign(2*size,neutral);
    }
    void set(int i,int v,int x,int lx,int rx){
        if(rx-lx==1){
            query[x]=single(v);
            return;
        }
        int m=(lx+rx)/2;
        if(i<m)
            set(i,v,2*x+1,lx,m);
        else
            set(i,v,2*x+2,m,rx);
        query[x]=merge(query[2*x+1],query[2*x+2]);
    }
    void set(int i,int v){
        set(i,v,0,0,size);
    }
    node calc(int l,int r,int x,int lx,int rx){
        if(lx>=r || rx<=l)
            return neutral;
        if(l<=lx && rx<=r)
            return query[x];
        int m=(lx+rx)/2;
        node a=calc(l,r,2*x+1,lx,m);
        node b=calc(l,r,2*x+2,m,rx);
        return merge(a,b);
    }
    int calc(int l,int r){
        return calc(l,r,0,0,size).maxd;
    }
};
int f(V<int>&A,int n,int x){
    map<int,int>mp;
    V<int>mp1(2e5+1);
    V<int>B=A;
    sort(all(B));
    int cnt=1;
    for(int i=0;i<n;i++){
        if(mp[B[i]]==0){
            mp[B[i]]=cnt;
            mp1[cnt]=B[i];
            cnt++;
        }
    }
    V<int>id(n);
    for(int i=0;i<n;i++){
        id[i]=mp[A[i]];
    }
    V<int>dp0(cnt,0);
    V<int>dp1(cnt,0);
    segtree tree0,tree1;
    tree0.init(cnt);
    tree1.init(cnt);
    for(int i=0;i<n;i++){
        dp0[id[i]]=max(dp0[id[i]],tree0.calc(0,id[i])+1);
        int ans=-1;
        int l=mp[id[i]],r=cnt-1;
        while(l<=r){
            int m=l+(r-l)/2;
            if(mp1[m]-A[i]<x){
                ans=m;
                l=m+1;
            }
            else
                r=m-1;
        }
        if(ans!=-1){
            dp1[id[i]]=max(dp1[id[i]],tree0.calc(0,ans+1)+1);
        }
        dp1[id[i]]=max(dp1[id[i]],tree1.calc(0,id[i])+1);
        tree0.set(id[i],dp0[id[i]]);
        tree1.set(id[i],dp1[id[i]]);
    }
    int ans=0;
    for(int i=1;i<cnt;i++){
        ans=max(ans,dp1[i]);
        ans=max(ans,dp0[i]);
    }
    return ans;
}
void solve() {
    int n;
    cin >> n;
    int x;
    cin >> x;
    V<int> A(n);
    for (int i = 0; i < n; i++) {
        cin >> A[i];
    }
    int ans = f(A, n, x);
    cout<<ans<<"\n";
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    //file();
   solve();
}

Compilation message (stderr)

glo.cpp: In function 'void file()':
glo.cpp:11:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 |     freopen("input.txt.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:12:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   12 |     freopen("output.txt.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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