Submission #1017604

#	Time	Username	Problem	Language	Result	Execution time	Memory
1017604		vjudge1	Feast (NOI19_feast)	C++17	0 / 100	8 ms	2140 KiB

feast

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define endl '\n'
#define ll long long
#define int long long
const long long inf=1e18;
const int MOD=998244353;
const int N=1e5+5;
int n,k,a[N];
pair<int,int> dp[N][2];
int func(int lambda){
    dp[0][0]={0,0};//empty
    dp[0][1]={-lambda,1};//using it
    for(int i=1;i<=n;i++){
        dp[i][0]=max(dp[i-1][0],dp[i-1][1]);
        int x=dp[i-1][0].first-lambda+a[i],y=dp[i-1][1].first+a[i];
        if(x>y){
            dp[i][1].first=x;
            dp[i][1].second=dp[i-1][0].second+1;
        }
        else{
            dp[i][1].first=y;
            dp[i][1].second=dp[i-1][1].second;
        }
    }
    int x=dp[n][0].first,y=dp[n][1].first;
    return (x>y?dp[n][0].second:dp[n][1].second);
}
signed main() {
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n>>k;
    for(int i=1;i<=n;i++)cin>>a[i];
    int l=0,r=1e18;
    while(l<r){
        int mid=(l+r+1)/2;
        int x=func(mid);
        if(x>=k)l=mid;
        else r=mid-1;
    }
    func(l);
    cout<<max(dp[n][0].first+l*dp[n][0].second,dp[n][1].first+l*dp[n][1].second);
}

• Subtask 1: 0 / 4
• Subtask 2: 0 / 8
• Subtask 3: 0 / 18
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11
• Subtask 6: 0 / 20
• Subtask 7: 0 / 29