oj.uz

답안 #669551

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
669551 2022-12-06T17:33:38 Z four_specks Building Bridges (CEOI17_building) C++17
100 / 100
 51 ms 8876 KB 
#include <bits/stdc++.h>

using namespace std;

inline namespace
{
    template <typename T>
    T fl_div(T a, T b) { return a / b - ((a ^ b) < 0 && a % b); }

    template <typename T>
    struct Line
    {
        T m, c;
        T operator()(T x) const { return m * x + c; }
    };

    template <typename T>
    struct LineContainerObject
    {
        T m, c;
        mutable T p;

        bool operator<(const LineContainerObject &i_line) const { return m < i_line.m; }
        bool operator<(T x) const { return p < x; }
    };

    template <typename T>
    struct LineContainer : multiset<LineContainerObject<T>, less<>>
    {
        void add(const Line<T> &line)
        {
            auto it = Base::insert({line.m, line.c, 0});
            while (isect(it))
                Base::erase(next(it));
            if (it != Base::begin())
            {
                it--;
                if (isect(it))
                {
                    Base::erase(next(it));
                    isect(it);
                }
            }
            while (it != Base::begin() && prev(it)->p >= it->p)
            {
                (it = Base::erase(it))--;
                isect(it);
            }
        }

        T query(T x)
        {
            auto it = Base::lower_bound(x);
            return it->m * x + it->c;
        }

    private:
        using Base = multiset<LineContainerObject<T>, less<>>;
        using Iterator = typename Base::iterator;

        inline static const T INF = numeric_limits<T>::max();

        bool isect(Iterator it)
        {
            if (next(it) == Base::end())
            {
                it->p = INF;
                return 0;
            }

            if (it->m == next(it)->m)
                it->p = it->c > next(it)->c ? INF : -INF;
            else
                it->p = fl_div(next(it)->c - it->c, it->m - next(it)->m);

            return it->p >= next(it)->p;
        }
    };

} // namespace

void solve()
{
    int n;
    cin >> n;

    vector<long> h(n), w(n);
    for (long &x : h)
        cin >> x;
    for (long &x : w)
        cin >> x;

    long add = 0;
    for (long x : w)
        add += x;

    vector<long> dp(n);
    LineContainer<long> cht;
    dp[0] = w[0];
    cht.add(Line<long>{2 * h[0], dp[0] - h[0] * h[0]});
    for (int i = 1; i < n; i++)
    {
        dp[i] = cht.query(h[i]) - h[i] * h[i] + w[i];
        cht.add(Line<long>{2 * h[i], dp[i] - h[i] * h[i]});
    }

    cout << -dp[n - 1] + add << '\n';
}

int main()
{
    ios_base::sync_with_stdio(false), cin.tie(NULL);

    solve();

    return 0;
}

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 41 ms 2716 KB Output is correct
2 Correct 41 ms 2644 KB Output is correct
3 Correct 40 ms 2644 KB Output is correct
4 Correct 38 ms 2644 KB Output is correct
5 Correct 41 ms 3800 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 41 ms 2716 KB Output is correct
7 Correct 41 ms 2644 KB Output is correct
8 Correct 40 ms 2644 KB Output is correct
9 Correct 38 ms 2644 KB Output is correct
10 Correct 41 ms 3800 KB Output is correct
11 Correct 40 ms 2712 KB Output is correct
12 Correct 40 ms 2724 KB Output is correct
13 Correct 32 ms 2668 KB Output is correct
14 Correct 39 ms 2644 KB Output is correct
15 Correct 51 ms 8876 KB Output is correct
16 Correct 38 ms 3864 KB Output is correct
17 Correct 21 ms 2644 KB Output is correct
18 Correct 24 ms 2660 KB Output is correct