Submission #1113198

#	Time	Username	Problem	Language	Result	Execution time	Memory
1113198		HiepVu217	Feast (NOI19_feast)	C++17	18 / 100	43 ms	8168 KiB

feast

#include <bits/stdc++.h>
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
using namespace std;
const int N = 3e5 + 17;
int n, k;
long long a[N];
pair <long long, int> f[N], m;
inline pair <long long, int> calc (long long c)
{
    f[0] = m = {0, 0};
    for (int i = 1; i <= n; ++i)
    {
        f[i] = f[i - 1];
        if (m.first + a[i] - c > f[i].first || (m.first + a[i] - c == f[i].first && m.second + 1 < f[i].second))
        {
            f[i].first = m.first + a[i] - c;
            f[i].second = m.second + 1;
        }
        if (f[i].first - a[i] > m.first || (f[i].first - a[i] == m.first && f[i].second < m.second))
        {
            m.first = f[i].first - a[i];
            m.second = f[i].second;
        }
    }
    return f[n];
}
int 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];
        a[i] += a[i - 1];
    }
    long long l = 1, r = 3e14;
    while (l < r)
    {
        long long mid = l + r >> 1;
        m = calc (mid);
        if (m.second == k)
        {
            cout << mid * k + m.first;
            return 0;
        }
        if (m.second > k)
        {
            l = mid + 1;
            continue;
        }
        r = mid - 1;
    }
    long long ans = l * k + calc(l).first;
    cout << ans;
}

Compilation message (stderr)

feast.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization ("O3")
      | 
feast.cpp:3: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    3 | #pragma GCC optimization ("unroll-loops")
      | 
feast.cpp: In function 'int main()':
feast.cpp:42:27: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   42 |         long long mid = l + r >> 1;
      |                         ~~^~~

• 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