Submission #716106

#	Time	Username	Problem	Language	Result	Execution time	Memory
716106		Baytoro	Global Warming (CEOI18_glo)	C++17	100 / 100	118 ms	8468 KiB

glo

#include <bits/stdc++.h>
using namespace std;
#define ios ios::sync_with_stdio(false); cin.tie(NULL);cout.tie(NULL);
#define pb push_back
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define fr first
#define sc second
#define endl '\n'
#define ll long long
#define int long long
void fopn(string name){
	freopen((name+".in").c_str(),"r",stdin);
	freopen((name+".out").c_str(),"w",stdout);
}
const ll INF=1e18,mod=1e9+7,N=1e5+5;
int n,x;
int a[2*N],pref[2*N];
void solve(){
	cin>>n>>x;
	vector<int> vec(n,INF);
	for(int i=0;i<n;i++){
		cin>>a[i];
	}
	int ans=0;
	for(int i=0;i<n;i++){
		int it=lower_bound(all(vec),a[i])-vec.begin();
		vec[it]=a[i];
		pref[i]=it+1;
		ans=max(ans,it+1);
	}
	vec=vector<int> (n,INF);
	reverse(a,a+n);
	for(int i=0;i<n;i++){
		int it=lower_bound(all(vec),x-a[i])-vec.begin();
		ans=max(ans,pref[n-i-1]+it);
		it=lower_bound(all(vec),-a[i])-vec.begin();
		vec[it]=-a[i];
	}
	cout<<ans;
}
main(){
	//fopn("cbarn");
	//ios;
	int T=1;
	//cin>>T;
	for(int i=1;i<=T;i++){
		//cout<<"Case #"<<i<<": ";
		solve();
	}
}

Compilation message (stderr)

glo.cpp:42:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   42 | main(){
      | ^~~~
glo.cpp: In function 'void fopn(std::string)':
glo.cpp:13:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |  freopen((name+".in").c_str(),"r",stdin);
      |  ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
glo.cpp:14:9: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |  freopen((name+".out").c_str(),"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