Submission #733384

#	Time	Username	Problem	Language	Result	Execution time	Memory
733384		finn__	Feast (NOI19_feast)	C++17	22 / 100	85 ms	5580 KiB

feast

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

constexpr size_t N = 300000;

int64_t a[N];

pair<int64_t, int64_t> dp(size_t n, int64_t lambda)
{
    int64_t mu = 0, nu = 0, p = 0, cnt = 0, _cnt = 0;
    for (size_t i = 0; i < n; ++i)
    {
        p += a[i];
        if (mu + p - lambda > nu)
            nu = mu + p - lambda, _cnt = cnt + 1;
        if (nu - p > mu)
            cnt = _cnt, mu = nu - p;
    }
    return {nu, cnt};
}

int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);

    size_t n, k;
    cin >> n >> k;
    for (size_t i = 0; i < n; ++i)
        cin >> a[i];

    int64_t u = 0, v = 1LL << 55;
    while (u < v)
    {
        if (dp(n, (u + v) / 2).second <= k)
            v = (u + v) / 2;
        else
            u = (u + v) / 2 + 1;
    }
    auto const [objective_val, cnt] = dp(n, u);
    cout << objective_val + k * u << '\n';
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:35:39: warning: comparison of integer expressions of different signedness: 'long int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   35 |         if (dp(n, (u + v) / 2).second <= k)
      |             ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~

• Subtask 1: 4 / 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