Submission #244021

#	Time	Username	Problem	Language	Result	Execution time	Memory
244021		Kubin	Aliens (IOI16_aliens)	C++17	12 / 100	235 ms	2424 KiB

aliens

#include <bits/stdc++.h>

using namespace std;

struct line
{
    int64_t a, b;
    int64_t operator() (int64_t x) const { return a*x + b; }
};

vector<pair<int, int>> filter_dominated(vector<pair<int, int>> I)
{
    vector<pair<int, int>> J = {{INT_MIN, INT_MIN}};
    sort(I.begin(), I.end(), [](pair<int, int> lhs, pair<int, int> rhs) {
        return lhs.first != rhs.first ? lhs.first < rhs.first : lhs.second > rhs.second;
    });
    for(auto [l, r] : I)
        if(not (J.back().first <= l and r <= J.back().second))
            J.emplace_back(l, r);
    J.erase(J.begin());
    return J;
}
constexpr int64_t square(int64_t x) { return x*x; }

int64_t take_photos(int _n, int _m, int _k, vector<int> r, vector<int> c)
{
    size_t n = _n, m = _m, k = _k; (void)m;

    vector<pair<int, int>> I;
    for(size_t i = 0; i < n; i++)
        I.emplace_back(min(r[i], c[i]), max(r[i], c[i]));
    I = filter_dominated(I);
    n = I.size();

    vector<vector<int64_t>> cost(n+1, vector<int64_t>(k+1, INT64_MAX / 3));
    cost[0] = vector<int64_t>(k+1, 0);
    for(size_t i = 1; i <= n; i++)
    {
        for(size_t l = 1; l <= k; l++)
        {
            for(size_t j = 0; j < i; j++)
            {
                line fj {
                    -2 * I[j].first,
                    cost[j][l-1] + square(I[j].first) +
                     + square(max(0, (j ? I[j-1].second : -1) - I[j].first + 1))
                };
                auto x = I[i-1].second + 1;
                cost[i][l] = min(cost[i][l], square(x) + fj(x));
            }
        }
    }
    return cost[n][k];
}

#ifdef XHOVA
int main()
{
    cout << take_photos(5, 7, 2, {0, 4, 4, 4, 4}, {3, 4, 6, 5, 6}) << endl;
    cout << take_photos(2, 6, 2, {1, 4}, {4, 1}) << endl;
}
#endif

• Subtask 1: 0 / 4
• Subtask 2: 12 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40