Submission #241045

#	Time	Username	Problem	Language	Result	Execution time	Memory
241045		computerbox	Watching (JOI13_watching)	C++14	100 / 100	323 ms	32120 KiB

watching

#include <bits/stdc++.h>
#define FLASH ios_base::sync_with_stdio(0);
#define ll long long
#define debt(x,y)cout<<"#x = "<<(x)<<" and "<<"#y = "<<(y)<<endl;
#define deb(x)cout<<"#x = "<<(x)<<endl;
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define endl "\n"
#define arr(a,n) for(ll i=1;i<=n;i++) cout<<a[i]<<" "; cout << "\n";
#define vecc(a,n) for(ll i=0;i<n;i++) cout<<a[i]<<" "; cout << "\n";


using namespace std;

ll dp[2010][2010];
vector<ll>massiv;
ll n,p,q;

ll f(ll w)
{
  memset(dp,0,sizeof(dp));
  ll pointbig=0;
  ll pointsmall=0;
  for(ll i=0;i<n;i++)
  {
	while(pointsmall<n && massiv[i]-massiv[pointsmall]>=w)pointsmall++;
	while(pointbig<n && massiv[i]-massiv[pointbig]>=2*w)pointbig++; 
	for(ll j=0;j<=min(q,n);j++)
	{
	  if(j==0)
	  {
		if(pointsmall==0)dp[i][j]=1;  
		else dp[i][j]=dp[pointsmall-1][j]+1;
	  }
	  else
	  {
	   if(pointbig==0)dp[i][j]=0;
	   else if(pointsmall==0)dp[i][j]=min(dp[pointbig-1][j-1],1LL);
	   else dp[i][j]=min(dp[pointsmall-1][j]+1,dp[pointbig-1][j-1]); 	
	  } 
    } 
  }
  ll minn=LLONG_MAX;
  
  
  for(ll i=0;i<=min(q,n);i++)minn=min(minn,dp[n-1][i]);
  if(minn<=p)return 1;
  else return 0;	
}


int main(){
FLASH;
cin>>n>>p>>q;
for(ll i=1;i<=n;i++){ll x;cin>>x;massiv.pb(x);}

sort(all(massiv));
ll nac=0;
ll konec=massiv.back()+10;
ll minn=LONG_MAX;
while(nac+1<konec)
{
  ll mid=nac+(konec-nac)/2;
  ll check=f(mid);
  if(check==1){minn=min(minn,mid);konec=mid;}
  else nac=mid;	
}

cout<<minn<<endl;




return 0;
} 

• Subtask 1: 50 / 50
• Subtask 2: 50 / 50