src/ds/dynsgt.hpp

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• Last update: 2025-10-04 08:32:39+08:00
• Include: #include "src/ds/dynsgt.hpp"

Verified with

• test/ds/dynsgt.test.cpp

Code

template <typename Info>
struct SegTree {
  struct Node {
    Info info = {};
    int ls = -1, rs = -1;
  };
  int n, _pos, _l, _r, root;
  Info _v;
  vector<Node> tree;
  SegTree(int n) : n(n) { root = alloc({}); }
  void set(int pos, Info v) { _pos = pos, _v = v, set(root, 0, n); }
  Info sum(int l, int r) { return _l = l, _r = r, sum(root, 0, n); }

 private:
  int alloc(Node node) { return tree.PUSHB(move(node)), int(tree.size()) - 1; }
  void set(int p, int pl, int pr) {
    if (pr - pl == 1) return tree[p].info = _v, void();
    int ls = tree[p].ls, rs = tree[p].rs, mid = pl + (pr - pl) / 2;
    if (ls == -1) ls = tree[p].ls = alloc({});
    if (rs == -1) rs = tree[p].rs = alloc({});
    _pos < mid ? set(ls, pl, mid) : set(rs, mid, pr);
    tree[p].info = tree[ls].info + tree[rs].info;
  }
  Info sum(int p, int pl, int pr) {
    if (_r <= pl || pr <= _l || p == -1) return {};
    if (_l <= pl && pr <= _r) return tree[p].info;
    int ls = tree[p].ls, rs = tree[p].rs, mid = pl + (pr - pl) / 2;
    return sum(ls, pl, mid) + sum(rs, mid, pr);
  }
};
struct Info {
  int data = 2e9;
  friend Info operator+(const Info& lhs, const Info& rhs) {
    return {min(lhs.data, rhs.data)};
  }
};

#line 1 "src/ds/dynsgt.hpp"
template <typename Info>
struct SegTree {
  struct Node {
    Info info = {};
    int ls = -1, rs = -1;
  };
  int n, _pos, _l, _r, root;
  Info _v;
  vector<Node> tree;
  SegTree(int n) : n(n) { root = alloc({}); }
  void set(int pos, Info v) { _pos = pos, _v = v, set(root, 0, n); }
  Info sum(int l, int r) { return _l = l, _r = r, sum(root, 0, n); }

 private:
  int alloc(Node node) { return tree.PUSHB(move(node)), int(tree.size()) - 1; }
  void set(int p, int pl, int pr) {
    if (pr - pl == 1) return tree[p].info = _v, void();
    int ls = tree[p].ls, rs = tree[p].rs, mid = pl + (pr - pl) / 2;
    if (ls == -1) ls = tree[p].ls = alloc({});
    if (rs == -1) rs = tree[p].rs = alloc({});
    _pos < mid ? set(ls, pl, mid) : set(rs, mid, pr);
    tree[p].info = tree[ls].info + tree[rs].info;
  }
  Info sum(int p, int pl, int pr) {
    if (_r <= pl || pr <= _l || p == -1) return {};
    if (_l <= pl && pr <= _r) return tree[p].info;
    int ls = tree[p].ls, rs = tree[p].rs, mid = pl + (pr - pl) / 2;
    return sum(ls, pl, mid) + sum(rs, mid, pr);
  }
};
struct Info {
  int data = 2e9;
  friend Info operator+(const Info& lhs, const Info& rhs) {
    return {min(lhs.data, rhs.data)};
  }
};

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