Sliding Window Template

[[nodiscard]] auto slidingWindow(const std::vector<int>& vec, /* */) -> /* */{
  std::size_t l = 0;

  const auto addIndex = [&](std::size_t index){
    // TODO: expand bound
  };

  const auto removeIndex = [&](std::size_t index){
    // TODO: shrink bound
  };

  const auto updateBound = [&](std::size_t r){
    addIndex(r);

    while(/* TODO: condition that make bound invalid */){
      removeIndex(l);
      l++;
    }
  };

  for(std::size_t r = 0; r < vec.size(); r++){
    updateBound(r);
    // TODO: do things with your bounds
  }
}