Range Reverse Range Sum (verify/structures/treap/range_reverse_range_sum.test.cpp)

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Last update: 2025-12-12 22:29:00+01:00
Problem: https://judge.yosupo.jp/problem/range_reverse_range_sum

Depends on

Code

// @brief Range Reverse Range Sum
#define PROBLEM "https://judge.yosupo.jp/problem/range_reverse_range_sum"
#include "cp-algo/structures/treap/metas/reverse.hpp"
#include "cp-algo/structures/treap.hpp"
#include <bits/stdc++.h>

using namespace std;
using namespace cp_algo::structures::treap;

using meta = metas::reverse_meta<int64_t>;
using node_t = node<meta>;
using treap = node_t::treap;

void solve() {
    istream_iterator<int> input(cin);
    int n = *input++;
    int q = *input++;
    cp_algo::big_vector<treap> nodes(n);
    generate_n(begin(nodes), n, [&](){
        return node_t::make_treap(meta(*input++));
    });
    auto me = node_t::build(nodes);
    while(q--) {
        int t = *input++;
        int l = *input++;
        int r = *input++;
        if(t == 0) {
            node_t::exec_on_segment(me, l, r, [](auto &t) {
                _safe_meta(t, reverse = true);
            });
        } else {
            node_t::exec_on_segment(me, l, r, [](auto const& t) {
                cout << _safe_meta(t, sum) << "\n";
            });
        }
    }
}

signed main() {
    //freopen("input.txt", "r", stdin);
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    while(t--) {
        solve();
    }
}

#line 1 "verify/structures/treap/range_reverse_range_sum.test.cpp"
// @brief Range Reverse Range Sum
#define PROBLEM "https://judge.yosupo.jp/problem/range_reverse_range_sum"
#line 1 "cp-algo/structures/treap/metas/reverse.hpp"


#line 1 "cp-algo/structures/treap/metas/base.hpp"


#line 1 "cp-algo/structures/treap/common.hpp"


#define _safe(t, op) (t ? t->op : typename std::remove_reference_t<decltype(t->op)>())

#line 4 "cp-algo/structures/treap/metas/base.hpp"
#include <functional>
#include <algorithm>
#include <cstdint>
#define _safe_meta(i, op) _safe(i, _meta.op)
namespace cp_algo::structures::treap::metas {
    struct base_meta {
        void pull(auto const, auto const){}
        void push(auto&, auto&){}
    };
}

#line 1 "cp-algo/math/affine.hpp"


#include <optional>
#include <utility>
#include <cassert>
#include <tuple>
namespace cp_algo::math {
    // a * x + b
    template<typename base>
    struct lin {
        base a = 1, b = 0;
        std::optional<base> c;
        lin() {}
        lin(base b): a(0), b(b) {}
        lin(base a, base b): a(a), b(b) {}
        lin(base a, base b, base _c): a(a), b(b), c(_c) {}

        // polynomial product modulo x^2 - c
        lin operator * (const lin& t) {
            assert(c && t.c && *c == *t.c);
            return {a * t.b + b * t.a, b * t.b + a * t.a * (*c), *c};
        }

        // a * (t.a * x + t.b) + b
        lin apply(lin const& t) const {
            return {a * t.a, a * t.b + b};
        }

        void prepend(lin const& t) {
            *this = t.apply(*this);
        }

        base eval(base x) const {
            return a * x + b;
        }
    };

    // (ax+b) / (cx+d)
    template<typename base>
    struct linfrac {
        base a, b, c, d;
        linfrac(): a(1), b(0), c(0), d(1) {} // x, identity for composition
        linfrac(base a): a(a), b(1), c(1), d(0) {} // a + 1/x, for continued fractions
        linfrac(base a, base b, base c, base d): a(a), b(b), c(c), d(d) {}

        // composition of two linfracs
        linfrac operator * (linfrac t) const {
            return t.prepend(linfrac(*this));
        }

        linfrac operator-() const {
            return {-a, -b, -c, -d};
        }

        linfrac adj() const {
            return {d, -b, -c, a};
        }
        
        linfrac& prepend(linfrac const& t) {
            t.apply(a, c);
            t.apply(b, d);
            return *this;
        }

        // apply linfrac to A/B
        void apply(base &A, base &B) const {
            std::tie(A, B) = std::pair{a * A + b * B, c * A + d * B};
        }
    };
}

#line 6 "cp-algo/structures/treap/metas/reverse.hpp"
namespace cp_algo::structures::treap::metas {
        template<typename base>
        struct reverse_meta: base_meta {
            using lin = math::lin<base>;
            base val;
            size_t sz = 1;
            bool reverse = false;
            base sum = val;
            
            lin to_push = {};

            reverse_meta(base val): val(val) {}

            void pull(auto const L, auto const R) {
                sum = val + _safe_meta(L, sum) + _safe_meta(R, sum);
                sz = 1 + _safe_meta(L, sz) + _safe_meta(R, sz);
            }
            void add_push(lin const& t) {
                val = t.eval(val);
                sum = t.a * sum + t.b * sz;
                to_push.prepend(t);
            }
            void push(auto &L, auto &R) {
                if(reverse) {
                    reverse = false;
                    std::swap(L, R);
                    _safe_meta(L, reverse ^= 1);
                    _safe_meta(R, reverse ^= 1);
                }
                if(to_push.a != 1 || to_push.b != 0) {
                    _safe_meta(L, add_push(to_push));
                    _safe_meta(R, add_push(to_push));
                    to_push = {};
                }
            }
        };
}

#line 1 "cp-algo/structures/treap.hpp"


#line 1 "cp-algo/util/big_alloc.hpp"



#include <set>
#include <map>
#include <deque>
#include <stack>
#include <queue>
#include <vector>
#include <string>
#include <cstddef>
#include <iostream>
#include <generator>
#include <forward_list>

// Single macro to detect POSIX platforms (Linux, Unix, macOS)
#if defined(__linux__) || defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#  define CP_ALGO_USE_MMAP 1
#  include <sys/mman.h>
#else
#  define CP_ALGO_USE_MMAP 0
#endif

namespace cp_algo {
    template <typename T, size_t Align = 32>
    class big_alloc {
        static_assert( Align >= alignof(void*), "Align must be at least pointer-size");
        static_assert(std::popcount(Align) == 1, "Align must be a power of two");
    public:
        using value_type = T;
        template <class U> struct rebind { using other = big_alloc<U, Align>; };
        constexpr bool operator==(const big_alloc&) const = default;
        constexpr bool operator!=(const big_alloc&) const = default;

        big_alloc() noexcept = default;
        template <typename U, std::size_t A>
        big_alloc(const big_alloc<U, A>&) noexcept {}

        [[nodiscard]] T* allocate(std::size_t n) {
            std::size_t padded = round_up(n * sizeof(T));
            std::size_t align = std::max<std::size_t>(alignof(T),  Align);
#if CP_ALGO_USE_MMAP
            if (padded >= MEGABYTE) {
                void* raw = mmap(nullptr, padded,
                                PROT_READ | PROT_WRITE,
                                MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
                madvise(raw, padded, MADV_HUGEPAGE);
                madvise(raw, padded, MADV_POPULATE_WRITE);
                return static_cast<T*>(raw);
            }
#endif
            return static_cast<T*>(::operator new(padded, std::align_val_t(align)));
        }

        void deallocate(T* p, std::size_t n) noexcept {
            if (!p) return;
            std::size_t padded = round_up(n * sizeof(T));
            std::size_t align  = std::max<std::size_t>(alignof(T),  Align);
    #if CP_ALGO_USE_MMAP
            if (padded >= MEGABYTE) { munmap(p, padded); return; }
    #endif
            ::operator delete(p, padded, std::align_val_t(align));
        }

    private:
        static constexpr std::size_t MEGABYTE = 1 << 20;
        static constexpr std::size_t round_up(std::size_t x) noexcept {
            return (x + Align - 1) / Align * Align;
        }
    };

    template<typename T> using big_vector = std::vector<T, big_alloc<T>>;
    template<typename T> using big_basic_string = std::basic_string<T, std::char_traits<T>, big_alloc<T>>;
    template<typename T> using big_deque = std::deque<T, big_alloc<T>>;
    template<typename T> using big_stack = std::stack<T, big_deque<T>>;
    template<typename T> using big_queue = std::queue<T, big_deque<T>>;
    template<typename T> using big_priority_queue = std::priority_queue<T, big_vector<T>>;
    template<typename T> using big_forward_list = std::forward_list<T, big_alloc<T>>;
    using big_string = big_basic_string<char>;

    template<typename Key, typename Value, typename Compare = std::less<Key>>
    using big_map = std::map<Key, Value, Compare, big_alloc<std::pair<const Key, Value>>>;
    template<typename T, typename Compare = std::less<T>>
    using big_multiset = std::multiset<T, Compare, big_alloc<T>>;
    template<typename T, typename Compare = std::less<T>>
    using big_set = std::set<T, Compare, big_alloc<T>>;
    template<typename Ref, typename V = void>

    using big_generator = std::generator<Ref, V, big_alloc<std::byte>>;
}

// Deduction guide to make elements_of with big_generator default to big_alloc
namespace std::ranges {
    template<typename Ref, typename V>
    elements_of(cp_algo::big_generator<Ref, V>&&) -> elements_of<cp_algo::big_generator<Ref, V>&&, cp_algo::big_alloc<std::byte>>;
}


#line 1 "cp-algo/random/rng.hpp"


#include <chrono>
#include <random>
namespace cp_algo::random {
    std::mt19937_64 gen(
        std::chrono::steady_clock::now().time_since_epoch().count()
    );
    uint64_t rng() {
        return gen();
    }
}

#line 6 "cp-algo/structures/treap.hpp"
#include <array>
namespace cp_algo::structures::treap {
    template<typename meta>
    struct node {
        using treap = node*;
        meta _meta;
        int prior = (int)random::rng();
        size_t size = 1;
        treap children[2] = {nullptr, nullptr};
        enum subtree {L, R};

        node() {}
        node(meta _meta): _meta(_meta) {}
        node(meta _meta, int prior): _meta(_meta), prior(prior) {}

        static treap make_treap(auto...args) {
            return new node(args...);
        }

        treap pull() {
            _meta.pull(children[L], children[R]);
            size = 1 + _safe(children[L], size) + _safe(children[R], size);
            return this;
        }

        treap push() {
            _meta.push(children[L], children[R]);
            return this;
        }

        // set i-th child and pull metadata
        treap set(subtree i, treap t) {
            children[i] = t;
            return pull();
        }

        // push changes and detach the i-th child
        treap cut(subtree i) {
            return children[i];
        }

        static treap merge(treap A, treap B) {
            if(!_safe(A, push()) || !_safe(B, push())) {
                return A ? A : B;
            } else if(A->prior < B->prior) {
                return A->set(R, merge(A->cut(R), B));
            } else {
                return B->set(L, merge(A, B->cut(L)));
            }
        }

        // return {L, R}, where |L|=k or L=A when |A| < k
        static std::array<treap, 2> split(treap A, size_t k) {
            if(!_safe(A, push())) {
                return {nullptr, nullptr};
            } else if(_safe(A->children[L], size) >= k) {
                auto [split_L, split_R] = split(A->cut(L), k);
                return {split_L, A->set(L, split_R)};
            } else {
                k -= _safe(A->children[L], size) + 1;
                auto [split_L, split_R] = split(A->cut(R), k);
                return {A->set(R, split_L), split_R};
            }
        }

        static void exec_on_segment(treap &A, size_t l, size_t r, auto func) {
            auto [LM, R] = split(A, r);
            auto [L, M] = split(LM, l);
            func(M);
            A = merge(L, merge(M, R));
        }

        static void insert(treap &A, size_t pos, treap t) {
            auto [L, R] = split(A, pos);
            A = merge(L, merge(t, R));
        }

        static void erase(treap &A, size_t pos) {
            auto [L, MR] = split(A, pos);
            auto [M, R] = split(MR, 1);
            delete M;
            A = merge(L, R);
        }

        static void exec_on_each(treap &A, auto func) {
            if(A) {
                exec_on_each(A->children[L], func);
                func(A);
                exec_on_each(A->children[R], func);
            }
        }

        treap pull_all() {
            _safe(children[L], pull_all());
            _safe(children[R], pull_all());
            return pull();
        }

        treap push_all() {
            push();
            _safe(children[L], push_all());
            _safe(children[R], push_all());
            return this;
        }

        static treap build(auto const& nodes) {
            big_vector<treap> st;
            for(auto cur: nodes) {
                while(st.size() >= 2 && st[st.size() - 2]->prior > cur->prior) {
                    st.pop_back();
                }
                if(!st.empty() && st.back()->prior > cur->prior) {
                    cur->set(L, st.back());
                    st.pop_back();
                }
                if(!st.empty() && st.back()->prior < cur->prior) {
                    st.back()->set(R, cur);
                }
                st.push_back(cur);
            }
            return st.empty() ? nullptr : st[0]->pull_all();
        }
    };

    struct null_meta {
        void pull(auto const, auto const) {}
        void push(auto&, auto&) {}
    };
}

#line 5 "verify/structures/treap/range_reverse_range_sum.test.cpp"
#include <bits/stdc++.h>

using namespace std;
using namespace cp_algo::structures::treap;

using meta = metas::reverse_meta<int64_t>;
using node_t = node<meta>;
using treap = node_t::treap;

void solve() {
    istream_iterator<int> input(cin);
    int n = *input++;
    int q = *input++;
    cp_algo::big_vector<treap> nodes(n);
    generate_n(begin(nodes), n, [&](){
        return node_t::make_treap(meta(*input++));
    });
    auto me = node_t::build(nodes);
    while(q--) {
        int t = *input++;
        int l = *input++;
        int r = *input++;
        if(t == 0) {
            node_t::exec_on_segment(me, l, r, [](auto &t) {
                _safe_meta(t, reverse = true);
            });
        } else {
            node_t::exec_on_segment(me, l, r, [](auto const& t) {
                cout << _safe_meta(t, sum) << "\n";
            });
        }
    }
}

signed main() {
    //freopen("input.txt", "r", stdin);
    ios::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
    while(t--) {
        solve();
    }
}

Test cases

Env	Name	Status	Elapsed	Memory
g++	almost_t0_00	AC	571 ms	27 MB
g++	almost_t1_00	AC	512 ms	27 MB
g++	example_00	AC	5 ms	4 MB
g++	max_random_00	AC	593 ms	27 MB
g++	max_random_01	AC	582 ms	27 MB
g++	max_random_02	AC	601 ms	27 MB
g++	nq_01_00	AC	5 ms	4 MB
g++	nq_01_01	AC	4 ms	3 MB
g++	nq_01_02	AC	28 ms	4 MB
g++	nq_01_03	AC	5 ms	4 MB
g++	nq_01_04	AC	4 ms	4 MB
g++	nq_01_05	AC	22 ms	4 MB
g++	nq_01_06	AC	24 ms	18 MB
g++	nq_01_07	AC	30 ms	21 MB
g++	random_00	AC	451 ms	18 MB
g++	random_01	AC	346 ms	24 MB
g++	random_02	AC	494 ms	21 MB
g++	small_random_00	AC	121 ms	4 MB
g++	small_random_01	AC	73 ms	4 MB
g++	small_random_02	AC	102 ms	4 MB