您可以合并将散列表（例如std::**unordered_map**或absl::**flat_hash_map**）与interval tree（例如boost::icl::**interval_map**）组合：

#include <iostream>
#include <unordered_map>
#include <boost/icl/interval_map.hpp>

using boost::icl::interval;
using Table = boost::icl::interval_map<int, std::string>;
using Database = std::unordered_map<std::string, Table>;

std::string Query(Database& db, const std::string& table_name, int number) {
  auto table_it = db.find(table_name);
  if (table_it != db.end()) {
    auto& table = table_it->second;
    auto range_it = table.find(number);
    if (range_it != table.end()) {
      return range_it->second;
    }
  }
  return "Not Found";
}

int main() {
  Database db;
  db["One"].insert(std::make_pair(interval<int>::closed(5, 20), "Apple"));
  db["One"].insert(std::make_pair(interval<int>::closed(25, 50), "Boat"));
  db["One"].insert(std::make_pair(interval<int>::closed(60, 100), "Cow"));
  db["Two"] = db["One"];
  db["Three"].insert(std::make_pair(interval<int>::closed(5, 20), "Air"));
  db["Three"].insert(std::make_pair(interval<int>::closed(25, 50), "Bard"));
  db["Three"].insert(std::make_pair(interval<int>::closed(60, 100), "Camera"));
  std::cout << "Query(Two, 15): " << Query(db, "Two", 15) << '\n';
  std::cout << "Query(Three, 30): " << Query(db, "Three", 30) << '\n';
  std::cout << "Query(One, 65): " << Query(db, "One", 65) << '\n';
  return 0;
}

字符串

输出：

Query(Two, 15): Apple
Query(Three, 30): Bard
Query(One, 65): Cow

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