Submission #1215671

#	Time	Username	Problem	Language	Result	Execution time	Memory
1215671		timeflew	Feast (NOI19_feast)	C++20	18 / 100	75 ms	12104 KiB

feast

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

#define ll long long
#define ff first
#define ss second
#define all(x) x.begin(), x.end()

const int mxN=3e5;

ll a[mxN+1];
pair<ll, ll> dp[mxN+1][2];
ll n, k;

pair<ll, ll> f(ll p) {
    dp[0][0]={0, 0};
    dp[0][1]={a[0]-p, 1};
    for(int i=1; i<n; i++) {
        dp[i][0]=max(dp[i-1][0], dp[i-1][1]);
        dp[i][1]=max(make_pair(dp[i-1][0].ff+a[i]-p, dp[i-1][0].ss+1), make_pair(dp[i-1][1].ff+a[i], dp[i-1][1].ss));
    }
    return max(dp[n-1][0], dp[n-1][1]);
}

int main() {
    ios::sync_with_stdio(0); cin.tie(0);
    cin>>n>>k;
    for(int i=0; i<n; i++) {
        cin>>a[i];
    }
    ll l=-1e9, r=1e18;
    while(l<=r) {
        ll mid=(l+r)/2;
        if(f(mid).ss>k) {
            l=mid+1;
        } else {
            r=mid-1;
        }
    }
    cout<<f(l).ff+l*k;
    return 0;
}
//rating below 2400 must be solved orzorzorz

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