Submission #1212376

#	Time	Username	Problem	Language	Result	Execution time	Memory
1212376		nmhung	Feast (NOI19_feast)	C++20	100 / 100	117 ms	12276 KiB

feast

#include <bits/stdc++.h>
#define mp make_pair
#define int long long
#define pii pair<int,int>
#define fi first
#define se second

using namespace std;
const int mod=1e9 + 7;
const int maxN=5e5+7;

int n,k,a[maxN];
pii dp[2][maxN];

pii sol(int lmb)
{
   dp[0][0]={0,0};
   dp[1][0]={-lmb,1};
   for(int i=1; i<=n; i++)
   {
      dp[0][i]=max(dp[0][i-1],dp[1][i-1]);

      dp[1][i]=max(mp(dp[0][i-1].fi+a[i]-lmb,dp[0][i-1].se+1),mp(dp[1][i-1].fi+a[i],dp[1][i-1].se));
   }
   return max(dp[0][n],dp[1][n]);
}

signed main(){
   ios_base::sync_with_stdio(NULL);
   cin.tie(0); cout.tie(0);

   cin>>n>>k;
   for(int i=1; i<=n; i++) cin>>a[i];

   int l=0,r=1e18,ans=0;
   while(l<=r)
   {
      int mid=(l+r)/2;
      if(sol(mid).se>=k)
      {
         ans=mid;
         l=mid+1;
      }
      else r=mid-1;
   }

   cout<<sol(ans).fi+ans*k<<endl;

   return 0;
}

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 29 / 29