Submission #826309

#	Time	Username	Problem	Language	Result	Execution time	Memory
826309		gagik_2007	Global Warming (CEOI18_glo)	C++17	100 / 100	59 ms	5852 KiB

glo

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

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define ff first
#define ss second

ll ttt;
const ll INF=1e18;
const ll MOD=1e9+7;
const ll N=5007;
ll n,m,k;
vector<int>a;

vector<int>LIS_suffix(vector<int>&a){
    vector<int>dp;
    vector<int>ans;
    for(int i=0;i<a.size();i++){
        auto it=lower_bound(dp.begin(),dp.end(),a[i]);
        if(it==dp.end()){
            dp.push_back(a[i]);
        }
        else{
            dp[it-dp.begin()]=a[i];
        }
        it=lower_bound(dp.begin(),dp.end(),a[i+1]+k);
        if(it==dp.begin()){
            ans.push_back(0);
        }
        else{
            it--;
            ans.push_back(it-dp.begin()+1);
        }
    }
    return ans;
}

vector<int>LIS_prefix(vector<int>&a){
    vector<int>dp;
    vector<int>ans;
    for(int i=0;i<a.size();i++){
        auto it=lower_bound(dp.begin(),dp.end(),a[i]);
        if(it==dp.end()){
            dp.push_back(a[i]);
            ans.push_back(dp.size());
        }
        else{
            dp[it-dp.begin()]=a[i];
            ans.push_back(it-dp.begin()+1);
        }
    }
    return ans;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    // freopen("input.txt","r",stdin);
    // freopen("output.txt","w",stdout);
    cin>>n>>k;
    a.resize(n);
    for(int i=0;i<n;i++){
        cin>>a[i];
    }
    vector<int>pf=LIS_prefix(a);
    reverse(a.begin(),a.end());
    for(int i=0;i<a.size();i++){
        a[i]*=-1;
    }
    vector<int>sf=LIS_suffix(a);
    reverse(sf.begin(),sf.end());
    // for(int i=0;i<n;i++){
    //     cout<<i<<": "<<pf[i]<<" "<<sf[i]<<endl;
    // }
    int ans=pf.back();
    for(int i=1;i<n;i++){
        // cout<<pf[i-1]+sf[i]<<" ";
        ans=max(ans,pf[i-1]+sf[i]);
    }
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

glo.cpp: In function 'std::vector<int> LIS_suffix(std::vector<int>&)':
glo.cpp:22:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |     for(int i=0;i<a.size();i++){
      |                 ~^~~~~~~~~
glo.cpp: In function 'std::vector<int> LIS_prefix(std::vector<int>&)':
glo.cpp:45:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |     for(int i=0;i<a.size();i++){
      |                 ~^~~~~~~~~
glo.cpp: In function 'int main()':
glo.cpp:72:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   72 |     for(int i=0;i<a.size();i++){
      |                 ~^~~~~~~~~

• 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