Submission #931874

#	Time	Username	Problem	Language	Result	Execution time	Memory
931874		fryingduc	Feast (NOI19_feast)	C++17	100 / 100	306 ms	24924 KiB

feast

#include<bits/stdc++.h>
#define int long long
#define double long double
#define PB push_back
#define maxn 300007
#define bit(x,i) ((x>>i)&1)
#define S second
#define F first
#define MP make_pair

using namespace std;

typedef pair<int,int> pii;
typedef pair<double,double> pdd;
typedef pair<double,int> pdi;
const int inf = 1e9*3e5;
const int mod = 1e9+7;
const double PI = acos(-1);
const double eps = 1e-3;

int n,k,a[maxn];
pdi f[maxn][2];

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

bool check(double dak){
    f[0][0]={0,0};
    f[0][1]={-inf,0};
    for (int i=1;i<=n;i++){
        f[i][0]=max(f[i-1][0],f[i-1][1]);
        f[i][1]=max((pdi){f[i-1][1].F+a[i],f[i-1][1].S},(pdi){f[i-1][0].F+a[i]-dak,f[i-1][0].S+1});
    }
    int mim=max(f[n][0],f[n][1]).S;
    return mim>=k;
}

void solve(){
    double l=0,r=inf,dak;
    while (l+eps<r){
        double mid=(l+r)/2;
        if (check(mid)) l=mid;
        else r=mid;
    }
    dak=l;
    check(dak);
    int ans=round(dak*k+max(f[n][0],f[n][1]).F);
    cout<<ans;
}

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