Submission #920115

#	Time	Username	Problem	Language	Result	Execution time	Memory
920115		Faisal_Saqib	Global Warming (CEOI18_glo)	C++17	28 / 100	2045 ms	6480 KiB

glo

#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
const int N=2e5+100;
int a[N],cpy[N],n,x;
long long dp[N];
int suf[N];
int LIS()
{
	int ans=0;
	for(int i=0;i<=n;i++)
		dp[i]=3e9;
	dp[0]=-3e9;
	for(int i=0;i<n;i++)
		dp[lower_bound(dp,dp+n+1,cpy[i])-dp]=cpy[i];
	for(int i=0;i<=n;i++)
		if(dp[i]!=3e9)
			ans=max(ans,i);
	return ans;
}
int val[N];
void find_suf()
{
	int ans=0;
	for(int i=0;i<=n;i++)
	{
		val[i]=-3e9;
		dp[i]=3e9;
	}
	val[0]=3e9;
	dp[0]=-3e9;
	suf[n]=0;
	for(int i=n-1;i>=0;i--)
	{
		cpy[i]=-cpy[i];
		int xc=lower_bound(dp,dp+n+1,cpy[i])-dp;
		val[xc]=max(-cpy[i],val[xc]);// inside if or outside??
		if(xc>ans)
		{
			ans=xc;
		}
		dp[xc]=cpy[i];
		suf[i]=xc;
		cpy[i]=-cpy[i];
	}
	// for(int i=1;i<=n;i++)
		// val[i]=min(val[i-1],val[i]);
	// for(int i=n-1;i>0;i--)
		// val[i]=max(val[i],val[i+1]);
	// We LIS of length i we have maximum value of the first element equal to val[i]
	// for(int i=0;i<=n;i++)
	// {
		// cout<<val[i]<<' ';
	// }
	// cout<<endl;
}
long long dp1[N];
void find_suf1(int tpl)
{
	int ans=0;
	for(int i=0;i<=n;i++)
	{
		val[i]=-3e9;
		dp1[i]=3e9;
	}
	val[0]=3e9;
	dp1[0]=-3e9;
	for(int i=n-1;i>=tpl;i--)
	{
		cpy[i]=-cpy[i];
		int xc=lower_bound(dp1,dp1+n+1,cpy[i])-dp1;
		val[xc]=max(-cpy[i],val[xc]);
		if(xc>ans)
			ans=xc;
		dp1[xc]=cpy[i];
		cpy[i]=-cpy[i];
	}
}
void reset()
{
	for(int i=0;i<n;i++)
		cpy[i]=a[i];
}
int main()
{
	cin>>n>>x;
	for(int i=0;i<n;i++)
		cin>>a[i];
	reset();
	int ans=0;
	int final=LIS();
	for(int i=0;i<=n;i++)
		dp[i]=3e9;
	dp[0]=-3e9;
	for(int i=0;i<n;i++)
	{
		cpy[i]-=x;
		int xc=lower_bound(dp,dp+n+1,cpy[i])-dp;
		dp[xc]=cpy[i];
		find_suf1(i+1);
		int s=0;
		int e=n+1;
		while(s+1<e)
		{
			int mid=(s+e)/2;
			if(val[mid]>(cpy[i]))
			{
				s=mid;
			}
			else
			{
				e=mid;
			}
		}
		// if(i==3)
		// {
			// cout<<"st "<<i<<endl;
			// cout<<cpy[i]<<endl;
			// cout<<"for "<<xc<<' '<<s<<endl;
			// for(int j=0;j<=n;j++)
			// {
				// cout<<dp[j]<<' ';
			// }
			// cout<<endl;
		// }
		final=max(final,xc+s);
	}
	cout<<final<<'\n';
	return 0;
}

Compilation message (stderr)

glo.cpp: In function 'void find_suf()':
glo.cpp:29:10: warning: overflow in conversion from 'double' to 'int' changes value from '-3.0e+9' to '-2147483648' [-Woverflow]
   29 |   val[i]=-3e9;
      |          ^~~~
glo.cpp:32:9: warning: overflow in conversion from 'double' to 'int' changes value from '3.0e+9' to '2147483647' [-Woverflow]
   32 |  val[0]=3e9;
      |         ^~~
glo.cpp: In function 'void find_suf1(int)':
glo.cpp:65:10: warning: overflow in conversion from 'double' to 'int' changes value from '-3.0e+9' to '-2147483648' [-Woverflow]
   65 |   val[i]=-3e9;
      |          ^~~~
glo.cpp:68:9: warning: overflow in conversion from 'double' to 'int' changes value from '3.0e+9' to '2147483647' [-Woverflow]
   68 |  val[0]=3e9;
      |         ^~~
glo.cpp: In function 'int main()':
glo.cpp:92:6: warning: unused variable 'ans' [-Wunused-variable]
   92 |  int ans=0;
      |      ^~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 0 / 10
• Subtask 5: 0 / 20
• Subtask 6: 0 / 17
• Subtask 7: 0 / 25