Submission #1209997

#	Time	Username	Problem	Language	Result	Execution time	Memory
1209997		tuankhang13	Feast (NOI19_feast)	C++20	100 / 100	151 ms	12172 KiB

feast

#include<bits/stdc++.h>
#define int long long
#define pb push_back
#define fi first
#define se second
#define pii pair<int,int>
#define vc vector<vector<int>>
using namespace std;

const int MOD=1e9+7;
const int N=3e5+5;
int a[N];

pii solve(int n,int lb){
    pii dp[n][2];
    for(int i=0;i<n;++i){
        dp[i][1]=dp[i][0]={-1e18,0};
    }
    dp[0][0]={0,0};
    dp[0][1]={a[0]-lb,1};
    for(int i=1;i<n;++i){
        dp[i][0]=max(dp[i-1][0],dp[i-1][1]);
        pii dp1={dp[i-1][0].fi+a[i]-lb,dp[i-1][0].se+1};
        pii dp2={dp[i-1][1].fi+a[i],dp[i-1][1].se};
        dp[i][1]=max(dp1,dp2);
    }
    return max(dp[n-1][1],dp[n-1][0]);
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n,k;
    cin>>n>>k;
    for(int i=0;i<n;++i)cin>>a[i];
    int l=0;
    int r=1e18;
    int ld=0;
    while(l<=r){
        int mid=(l+r)/2;
        pii tmp=solve(n,mid);
        if(tmp.se>=k){
            ld=mid;
            l=mid+1;
        }
        else {
            r=mid-1;
        }
    }
    pii res=solve(n,ld);
    cout<<res.fi+ld*k;
}

• 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