Verify/segment_tree_rsq.test.cpp

• View this file on GitHub
• Last update: 2020-07-26 22:31:04+09:00
• Problem: https://judge.yosupo.jp/problem/point_add_range_sum

Depends on

• DataStructure/segment_tree.hpp

Code

#define PROBLEM "https://judge.yosupo.jp/problem/point_add_range_sum"

#include "../DataStructure/segment_tree.hpp"

#include <iostream>

using lint = long long;

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int n, q;
    std::cin >> n >> q;

    std::vector<lint> xs(n);
    for (auto& x : xs) std::cin >> x;
    SegmentTree<lint> seg(xs, 0, [](auto a, auto b) { return a + b; });

    while (q--) {
        int t;
        std::cin >> t;

        if (t == 0) {
            int i;
            lint x;
            std::cin >> i >> x;
            seg.update(i, seg.get(i) + x);

        } else {
            int l, r;
            std::cin >> l >> r;
            std::cout << seg.fold(l, r) << "\n";
        }
    }

    return 0;
}

#line 1 "Verify/segment_tree_rsq.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/point_add_range_sum"

#line 2 "DataStructure/segment_tree.hpp"

#include <vector>
#include <functional>

template <class T>
struct SegmentTree {
    using Merger = std::function<T(T, T)>;

    int length;
    std::vector<T> dat;
    T unit;
    Merger merge;

    SegmentTree() = default;

    SegmentTree(int n, const T& unit, const Merger& merge)
        : length(1), unit(unit), merge(merge) {
        while (length < n) length <<= 1;
        dat.assign(length * 2, unit);
    }

    template <class Container>
    SegmentTree(const Container& elems, const T& unit, const Merger& merge)
        : length(1), unit(unit), merge(merge) {
        int n = elems.size();
        while (length < n) length <<= 1;

        dat.assign(length * 2, unit);

        std::copy(elems.begin(), elems.end(), dat.begin() + length);

        for (int nidx = length - 1; nidx >= 1; --nidx) {
            T vl = dat[nidx * 2 + 0];
            T vr = dat[nidx * 2 + 1];
            dat[nidx] = merge(vl, vr);
        }
    }

    void update(int nidx, const T& elem) {
        nidx += length;
        dat[nidx] = elem;

        while (nidx > 0) {
            nidx >>= 1;
            T vl = dat[nidx * 2 + 0];
            T vr = dat[nidx * 2 + 1];
            dat[nidx] = merge(vl, vr);
        }
    }

    T fold(int ql, int qr) const {
        ql = std::max(ql, 0);
        qr = std::min(qr, length);
        ql += length, qr += length;

        T lacc = unit, racc = unit;
        while (ql < qr) {
            if (ql & 1) {
                lacc = merge(lacc, dat[ql]);
                ++ql;
            }
            if (qr & 1) {
                --qr;
                racc = merge(dat[qr], racc);
            }
            ql >>= 1, qr >>= 1;
        }

        return merge(lacc, racc);
    }

    T get(int idx) const { return dat[idx + length]; }
    T fold_all() const { return dat[1]; }
};
#line 4 "Verify/segment_tree_rsq.test.cpp"

#include <iostream>

using lint = long long;

int main() {
    std::cin.tie(nullptr);
    std::ios::sync_with_stdio(false);

    int n, q;
    std::cin >> n >> q;

    std::vector<lint> xs(n);
    for (auto& x : xs) std::cin >> x;
    SegmentTree<lint> seg(xs, 0, [](auto a, auto b) { return a + b; });

    while (q--) {
        int t;
        std::cin >> t;

        if (t == 0) {
            int i;
            lint x;
            std::cin >> i >> x;
            seg.update(i, seg.get(i) + x);

        } else {
            int l, r;
            std::cin >> l >> r;
            std::cout << seg.fold(l, r) << "\n";
        }
    }

    return 0;
}

Back to top page