제출 #402673

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
402673		KoD	Bulldozer (JOI17_bulldozer)	C++17	100 / 100	681 ms	94436 KiB

bulldozer

#include <bits/stdc++.h>

using i32 = std::int32_t;
using u32 = std::uint32_t;
using i64 = std::int64_t;
using u64 = std::uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using isize = std::ptrdiff_t;
using usize = std::size_t;

class rep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { ++itr; }
        constexpr bool operator!=(const Iter& other) const noexcept { return itr != other.itr; }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr rep(const usize first, const usize last) noexcept : first(first), last(std::max(first, last)) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

template <class T, T Div = 2> constexpr T INFTY = std::numeric_limits<T>::max() / Div;

template <class T> bool setmax(T& lhs, const T& rhs) {
    if (lhs < rhs) {
        lhs = rhs;
        return true;
    }
    return false;
}

class revrep {
    struct Iter {
        usize itr;
        constexpr Iter(const usize pos) noexcept : itr(pos) {}
        constexpr void operator++() noexcept { --itr; }
        constexpr bool operator!=(const Iter& other) const noexcept { return itr != other.itr; }
        constexpr usize operator*() const noexcept { return itr; }
    };
    const Iter first, last;

  public:
    explicit constexpr revrep(const usize first, const usize last) noexcept
        : first(last - 1), last(std::min(first, last) - 1) {}
    constexpr Iter begin() const noexcept { return first; }
    constexpr Iter end() const noexcept { return last; }
};

constexpr u64 ceil_log2(const u64 x) {
    u64 e = 0;
    while (((u64)1 << e) < x) ++e;
    return e;
}

template <class Monoid> class SegmentTree {
    using M = Monoid;
    usize internal_size, seg_size;
    std::vector<M> data;

    void fetch(const usize k) { data[k] = data[2 * k] + data[2 * k + 1]; }

  public:
    explicit SegmentTree(const usize size = 0, const M& value = M::zero()) : SegmentTree(std::vector<M>(size, value)) {}
    explicit SegmentTree(const std::vector<M>& vec) : internal_size(vec.size()) {
        seg_size = 1 << ceil_log2(internal_size);
        data = std::vector<M>(2 * seg_size, M::zero());
        for (const usize i : rep(0, internal_size)) data[seg_size + i] = vec[i];
        for (const usize i : revrep(1, seg_size)) fetch(i);
    }

    usize size() const { return internal_size; }

    void assign(usize i, const M& value) {
        assert(i < internal_size);
        i += seg_size;
        data[i] = value;
        while (i > 1) {
            i >>= 1;
            fetch(i);
        }
    }

    M fold() const { return data[1]; }
    M fold(usize l, usize r) const {
        assert(l <= r and r <= internal_size);
        l += seg_size;
        r += seg_size;
        M ret_l = M::zero(), ret_r = M::zero();
        while (l < r) {
            if (l & 1) ret_l = ret_l + data[l++];
            if (r & 1) ret_r = data[--r] + ret_r;
            l >>= 1;
            r >>= 1;
        }
        return ret_l + ret_r;
    }

    template <class F> usize max_right(usize l, const F& f) const {
        assert(l <= internal_size);
        assert(f(M::zero()));
        if (l == internal_size) return internal_size;
        l += seg_size;
        M sum = M::zero();
        do {
            while (!(l & 1)) l >>= 1;
            if (!f(sum + data[l])) {
                while (l < seg_size) {
                    l = 2 * l;
                    if (f(sum + data[l])) sum = sum + data[l++];
                }
                return l - seg_size;
            }
            sum = sum + data[l++];
        } while ((l & -l) != l);
        return internal_size;
    }

    template <class F> usize min_left(usize r, const F& f) const {
        assert(r <= internal_size);
        assert(f(M::zero()));
        if (r == 0) return 0;
        r += seg_size;
        M sum = M::zero();
        do {
            r -= 1;
            while (r > 1 and (r & 1)) r >>= 1;
            if (!f(data[r] + sum)) {
                while (r < seg_size) {
                    r = 2 * r + 1;
                    if (f(data[r] + sum)) sum = data[r--] + sum;
                }
                return r + 1 - seg_size;
            }
            sum = data[r] + sum;
        } while ((r & -r) != r);
        return 0;
    }
};

template <class T> using Vec = std::vector<T>;

struct Query {
    i64 x, y;
    usize i, j;
    bool operator<(const Query& other) const { return (x * other.y) - (y * other.x) > 0; }
};

struct Monoid {
    i64 min, max, dif;
    Monoid(const i64 min, const i64 max, const i64 dif) : min(min), max(max), dif(dif) {}
    Monoid(const i64 val = 0) : min(val), max(val), dif(0) {}
    static Monoid zero() { return Monoid(INFTY<i64>, -INFTY<i64>, -INFTY<i64>); }
    Monoid operator+(const Monoid& other) const {
        return Monoid(std::min(min, other.min), std::max(max, other.max), std::max({dif, other.dif, other.max - min}));
    }
};

void JOI17_bulldozer_main() {
    usize N;
    std::cin >> N;
    Vec<i64> X(N), Y(N), W(N);
    for (const auto i : rep(0, N)) {
        std::cin >> X[i] >> Y[i] >> W[i];
    }
    Vec<usize> order(N);
    std::iota(order.begin(), order.end(), (usize)0);
    std::sort(order.begin(), order.end(),
              [&](const usize i, const usize j) { return X[i] < X[j] or (X[i] == X[j] and Y[i] < Y[j]); });
    Vec<Query> swap;
    swap.reserve(N * (N - 1) / 2);
    for (const auto i : order) {
        for (const auto j : order) {
            if (i == j) {
                continue;
            }
            const auto x = Y[i] - Y[j];
            const auto y = X[j] - X[i];
            if (y < 0 or (x > 0 and y == 0)) {
                continue;
            }
            swap.push_back(Query{x, y, i, j});
        }
    }
    std::stable_sort(swap.begin(), swap.end());
    Vec<i64> sum(N + 1);
    Vec<Monoid> mnd(N + 1);
    Vec<usize> inv(N);
    for (const auto i : rep(0, N)) {
        const auto k = order[i];
        sum[i + 1] = sum[i] + W[k];
        mnd[i + 1] = Monoid(sum[i + 1]);
        inv[k] = i;
    }
    SegmentTree<Monoid> seg(mnd);
    i64 ans = -INFTY<i64>;
    Query last{1, 0, 0, 0};
    for (const auto& dir : swap) {
        if (last < dir) {
            last = dir;
            setmax(ans, seg.fold().dif);
        }
        auto i = dir.i, j = dir.j;
        if (inv[i] > inv[j]) {
            std::swap(i, j);
        }
        const auto l = inv[i];
        const auto r = inv[j];
        assert(l + 1 == r);
        sum[l + 1] = sum[l] + W[j];
        sum[r + 1] = sum[l + 1] + W[i];
        seg.assign(l + 1, Monoid(sum[l + 1]));
        seg.assign(r + 1, Monoid(sum[r + 1]));
        inv[i] = r;
        inv[j] = l;
    }
    setmax(ans, seg.fold().dif);
    std::cout << ans << '\n';
}

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    JOI17_bulldozer_main();
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 20 / 20
• Subtask 3: 35 / 35
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20