Submission #808682

#	Time	Username	Problem	Language	Result	Execution time	Memory
808682		finn__	Tortoise (CEOI21_tortoise)	C++17	0 / 100	1 ms	596 KiB

tortoise

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

constexpr size_t N = 300;

int32_t f[N << 1][N], a[N], x[N], u[N], v[N];

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

    for (size_t i = 0; i < N; ++i)
        fill(f[i], f[i] + N, INT32_MIN);

    size_t n, m = 0, last_playground = -1;
    cin >> n;

    int32_t sum_a = 0;
    for (size_t i = 0; i < n; ++i)
    {
        cin >> a[i];
        if (a[i] >= 0)
            x[m] = i, u[m] = last_playground, sum_a += a[i], ++m;
        else
            last_playground = i;
    }

    last_playground = n;
    for (size_t i = n - 1, j = m - 1; i < n; --i)
    {
        if (a[i] >= 0)
            v[j] = last_playground, --j;
        else
            last_playground = i;
    }

    for (size_t i = 0; i < m; ++i)
        f[x[i]][i] = 0;

    int32_t ans = 0;
    for (size_t i = 0; i < n << 1; ++i)
        for (size_t j = 0; j < m; ++j)
        {
            ans = max(ans, f[i][j] + (i <= (x[j] << 1)));
            for (size_t k = j + 1; k < m; ++k)
            {
                // Don't pick up the candy at the j-th shop.
                if (i + x[k] - x[j] < n << 1)
                    f[i + x[k] - x[j]][k] = max(f[i + x[k] - x[j]][k], f[i][j]);
                // Bring the candy of the j-th shop to the preceding playground.
                if (i <= (x[j] << 1) && u[j] != -1 && i + x[j] + x[k] - (u[j] << 1) < (n << 1))
                    f[i + x[j] + x[k] - (u[j] << 1)][k] = max(f[i + x[j] + x[k] - (u[j] << 1)][k], f[i][j] + 1);
                // Bring the candy of the j-th shop to the next playground.
                if (i <= (x[j] << 1) && v[j] != n && i + v[j] - x[j] + abs(x[k] - v[j]) < (n << 1))
                    f[i + v[j] - x[j] + abs(x[k] - v[j])][k] = max(f[i + v[j] - x[j] + abs(x[k] - v[j])][k], f[i][j] + 1);
            }
        }

    cout << sum_a - ans << '\n';
}

Compilation message (stderr)

tortoise.cpp: In function 'int main()':
tortoise.cpp:45:41: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int32_t' {aka 'int'} [-Wsign-compare]
   45 |             ans = max(ans, f[i][j] + (i <= (x[j] << 1)));
      |                                       ~~^~~~~~~~~~~~~~
tortoise.cpp:52:23: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int32_t' {aka 'int'} [-Wsign-compare]
   52 |                 if (i <= (x[j] << 1) && u[j] != -1 && i + x[j] + x[k] - (u[j] << 1) < (n << 1))
      |                     ~~^~~~~~~~~~~~~~
tortoise.cpp:55:23: warning: comparison of integer expressions of different signedness: 'size_t' {aka 'long unsigned int'} and 'int32_t' {aka 'int'} [-Wsign-compare]
   55 |                 if (i <= (x[j] << 1) && v[j] != n && i + v[j] - x[j] + abs(x[k] - v[j]) < (n << 1))
      |                     ~~^~~~~~~~~~~~~~
tortoise.cpp:55:46: warning: comparison of integer expressions of different signedness: 'int32_t' {aka 'int'} and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
   55 |                 if (i <= (x[j] << 1) && v[j] != n && i + v[j] - x[j] + abs(x[k] - v[j]) < (n << 1))
      |                                         ~~~~~^~~~

• Subtask 1: 0 / 8
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 25
• Subtask 5: 0 / 27