Submission #1144086

#	Time	Username	Problem	Language	Result	Execution time	Memory
1144086		nikolashami	Feast (NOI19_feast)	C++20	100 / 100	143 ms	12180 KiB

feast

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

#define mp make_pair
#define pr pair<ll,ll>
#define fi first
#define se second

const int N=3e5+4;
pr f[N][2];
ll a[N],n,k;

pr chk(ll x){
	f[0][0]={0,0};
	f[0][1]={-(ll)4e15,-(ll)4e15};
	for(int i=1;i<=n;++i){
		f[i][1]=max(mp(f[i-1][1].fi+a[i],f[i-1][1].se),mp(f[i-1][0].fi+a[i]-x,f[i-1][0].se+1));
		f[i][0]=max((pair<ll,ll>)f[i-1][0],(pair<ll,ll>)f[i-1][1]);
	}
	return(max({f[n][0],f[n][1]}));
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    
    cin>>n>>k;
    for(int i=1;i<=n;++i)
    	cin>>a[i];

    ll l=0,r=3e14,ans=0;
    while(l<=r){
    	ll λ=(l+r)/2;
    	auto R=chk(λ);
    	if(R.se>k)l=λ+1;
    	else{
    		ans=R.fi+λ*R.se;
    		r=λ-1;
    	}
    }
    
    cout<<ans;
}

• 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