Submission #1368576

#	Time	Username	Problem	Language	Result	Execution time	Memory
1368576		12345678	Feast (NOI19_feast)	C++17	100 / 100	89 ms	9804 KiB

feast

#include <bits/stdc++.h>

using namespace std;

#define ll long long

const ll nx=3e5+5, inf=1e18;

ll n, k, a[nx], qs[nx];

pair<ll, ll> solve(ll lambda)
{
    pair<ll, ll> mx;
    vector<pair<ll, ll>> dp(n+1, {-inf, 0});
    dp[0]={0, 0};
    for (int i=1; i<=n; i++)
    {
        mx=max(mx, {dp[i-1].first-qs[i], dp[i-1].second});
        dp[i]=max(dp[i-1], {mx.first+qs[i]-lambda, mx.second+1});
    }
    return dp[n];
}

int main()
{
    cin.tie(NULL)->sync_with_stdio(false);
    cin>>n>>k;
    for (int i=1; i<=n; i++) cin>>a[i], qs[i]=qs[i-1]+a[i];
    ll l=0, r=3e14;
    while (l<r)
    {
        ll md=(l+r+1)/2;
        if (solve(md).second>=k) l=md;
        else r=md-1;
    }
    cout<<solve(l).first+l*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