oj.uz

답안 #669579

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
669579 2022-12-06T19:07:16 Z four_specks Building Bridges (CEOI17_building) C++17
100 / 100
 54 ms 8908 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 = this->insert({line.m, line.c, 0});
            while (isect(it))
                this->erase(next(it));
            if (it != this->begin() && isect(--it))
            {
                this->erase(next(it));
                isect(it);
            }
            while (it != this->begin() && isect(--it))
            {
                this->erase(next(it));
                isect(it);
            }
        }

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

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

        bool isect(typename multiset<LineContainerObject<T>, less<>>::iterator it)
        {
            if (next(it) == this->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 0 ms 256 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 42 ms 2644 KB Output is correct
2 Correct 43 ms 2884 KB Output is correct
3 Correct 42 ms 2732 KB Output is correct
4 Correct 41 ms 2672 KB Output is correct
5 Correct 43 ms 3764 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 0 ms 256 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 42 ms 2644 KB Output is correct
7 Correct 43 ms 2884 KB Output is correct
8 Correct 42 ms 2732 KB Output is correct
9 Correct 41 ms 2672 KB Output is correct
10 Correct 43 ms 3764 KB Output is correct
11 Correct 49 ms 2672 KB Output is correct
12 Correct 42 ms 2644 KB Output is correct
13 Correct 34 ms 2672 KB Output is correct
14 Correct 42 ms 2724 KB Output is correct
15 Correct 54 ms 8908 KB Output is correct
16 Correct 43 ms 3788 KB Output is correct
17 Correct 28 ms 2644 KB Output is correct
18 Correct 21 ms 2668 KB Output is correct