library/segtree/DualSegmentTree.hpp

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• Last update: 2025-11-24 18:49:07+09:00
• Include: #include "library/segtree/DualSegmentTree.hpp"

Depends on

• build/pch/stdc++.hpp

Verified with

• test/AOJ/DSL_2_D.test.cpp
• test/AOJ/DSL_2_E.test.cpp
• test/yukicoder/1038.test.cpp

Code

template <typename Lazy> class DualSegmentTree {
    using MX = typename Lazy::MX;
    using MF = typename Lazy::MF;
    using X = typename MX::value_type;
    using F = typename MF::value_type;
    int n, log, size;
    std::vector<X> dat;
    std::vector<F> laz;

    void point_apply(int k, const F &f) {
        if (k < size)
            MF::Lchop(f, laz[k]);
        else
            dat[k - size] = Lazy::mapping(f, dat[k - size]);
    }
    void push(int k) {
        point_apply(2 * k, laz[k]);
        point_apply(2 * k + 1, laz[k]);
        laz[k] = MF::unit();
    }
    void thrust(int k) {
        for (int i = log; i; i--)
            push(k >> i);
    }

  public:
    DualSegmentTree() : DualSegmentTree(0) {}
    DualSegmentTree(int n) : DualSegmentTree(std::vector<X>(n, MX::unit())) {}
    DualSegmentTree(const std::vector<X> &v) : n(v.size()), dat(v) {
        for (log = 1; (1 << log) < n; log++) {
        }
        size = 1 << log;
        laz.assign(size, MF::unit());
    }

    void set(int p, X x) {
        assert(0 <= p and p < n);
        thrust(p + size);
        dat[p] = x;
    }

    X operator[](int p) {
        assert(0 <= p and p < n);
        thrust(p + size);
        return dat[p];
    }

    void apply(int l, int r, F f) {
        assert(0 <= l && l <= r && r <= n);
        if (l == r)
            return;
        thrust(l += size);
        thrust(r += size - 1);
        for (int L = l, R = r + 1; L < R; L >>= 1, R >>= 1) {
            if (L & 1)
                point_apply(L++, f);
            if (R & 1)
                point_apply(--R, f);
        }
    }
};

#line 1 "library/segtree/DualSegmentTree.hpp"
template <typename Lazy> class DualSegmentTree {
    using MX = typename Lazy::MX;
    using MF = typename Lazy::MF;
    using X = typename MX::value_type;
    using F = typename MF::value_type;
    int n, log, size;
    std::vector<X> dat;
    std::vector<F> laz;

    void point_apply(int k, const F &f) {
        if (k < size)
            MF::Lchop(f, laz[k]);
        else
            dat[k - size] = Lazy::mapping(f, dat[k - size]);
    }
    void push(int k) {
        point_apply(2 * k, laz[k]);
        point_apply(2 * k + 1, laz[k]);
        laz[k] = MF::unit();
    }
    void thrust(int k) {
        for (int i = log; i; i--)
            push(k >> i);
    }

  public:
    DualSegmentTree() : DualSegmentTree(0) {}
    DualSegmentTree(int n) : DualSegmentTree(std::vector<X>(n, MX::unit())) {}
    DualSegmentTree(const std::vector<X> &v) : n(v.size()), dat(v) {
        for (log = 1; (1 << log) < n; log++) {
        }
        size = 1 << log;
        laz.assign(size, MF::unit());
    }

    void set(int p, X x) {
        assert(0 <= p and p < n);
        thrust(p + size);
        dat[p] = x;
    }

    X operator[](int p) {
        assert(0 <= p and p < n);
        thrust(p + size);
        return dat[p];
    }

    void apply(int l, int r, F f) {
        assert(0 <= l && l <= r && r <= n);
        if (l == r)
            return;
        thrust(l += size);
        thrust(r += size - 1);
        for (int L = l, R = r + 1; L < R; L >>= 1, R >>= 1) {
            if (L & 1)
                point_apply(L++, f);
            if (R & 1)
                point_apply(--R, f);
        }
    }
};

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