제출 #1017730

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1017730		vjudge1	Feast (NOI19_feast)	C++17	100 / 100	103 ms	12172 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=3e5+5;
int n,k,a[N];
pair<int,int> dp[N][2];
pair<int,int> mx(pair<int,int> p1,pair<int,int> p2){
    if(p1.first==p2.first && p2.second<p1.second)swap(p1,p2);
    if(p2.first>p1.first)return p2;
    else return p1;
}
pair<int,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]=mx(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 || (x==y && dp[i-1][0]<dp[i-1][1])){
            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;
        }
    }
    return max(dp[n][0],dp[n][1]);
}
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=1e16;
    while(l<r){
        int mid=(l+r)/2;
        int x=func(mid).second;
        if(x>k)l=mid+1;
        else r=mid;
    }
    auto p = func(l);
    cout<<p.first+l*p.second;
}

• 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