samar1tan / project-map

a flawed, partial implementation of std::map

Project Map

Course Project for Data Structures：Based on Red-black tree, simply implemented std::map

Demo

#include "lib\simple_map.h" // for Windows. '\' --> '/' on Linux 
#include <string>
#include <iostream>

SimpleMap<int, std::string> foo;
foo.insert(Entry<int, std::string> (1220, "alpha"))
std::cout << foo[1220] << " version pushed on 1220" << std::endl;

alpha version pushed on 1220

Member types

• key_type Entry<Key, Value>.Key
• value_type Value
  • std::map::mapped_type
  • not std::map::value_type
• mapped_type the same as above
• element_type Entry<Key, Value>
  • std::map::value_type
• allocator_type RedBlackTree< Node<Entry<Key, Value> >
• iterator SimpleMap::MapIterator

Member functions

• (constructor)
• (destructor)
• operator=
• Iterators (Forward Iterator)
  • begin Return the iterator of the first Entry with min key of inorder traversal
  • end Return the iterator of the last Entry of inorder traversal, i.e., (SimpleMap::iterator)nullptr
• Capacity
  • empty Return true if empty, otherwise false
  • size Return the current number of Entry
  • max_size Return the theoretic max amount of Entry, i.e., UINT_MAX
• Element Access
  • operator[](k) return the reference of Entry.value where key == k, otherwise, insert new Entry with key == k and return the reference of its defaultly constructed value
  • find(k) Return the iterator of Entry of which the key is k, otherwise SimpleMap::end, i.e., (SimpleMap::const_iterator)nullptr
  • count(k) Return the count of Entry of which the key is k, i.e., 0 / 1
  • min Return the iterator pointing to Entry with the minimum key
  • max Return the iterator pointing to Entry with the maximum key
  • data Return the pointer to RBTree
• Modifiers
  • insert(element) Return iterator pointing to newly inserted Entry, otherwise pointing to the old element identified by key
  • erase(k) Delete Entry by key，returning true when successful, otherwise false
  • erase(position) Delete Entry by iterator，returning true when successful，otherwise false
  • clear() Delete all elements and re-allocate the storage position of Red-black tree in the heap

Implementation summary

• template class SimpleMap<Key, Value> fake std::map
  • template class Entry<Key, Value> the element of SimpleMap，fake std::pair
• template class RedBlackTree<node_data_type> Red Black Tree, in which node.data.key increases in inorder traversal
  • template class RedBlackTree : public SearchTree<node_data_type> : public Tree<node_data_type> put the implementation of Search Tree and Binary Tree into the parent classes of RBTree
  • template class Node<node_data_type> the node of the tree, of which node_data_type == Entry

Contributing

Coding style

• lib\red_black_tree\rbtree.h following Google C++ Style Guide
• lib\simple_map.h like std::map

Comments

There were plenty of comments in simple_map.h, including:

• the definition of interfaces
• implementation details
• TODOs

Acknowledgement & References

1. 《数据结构（C++语言版）（第3版）》 邓俊辉 清华大学出版社
2. map - C++ Reference

Checkpoints

• Test all behaviors of SimpleMap
• Further test the stability of Red-black tree performing random insertions and deletions
• Showcase the final gains
• Write the experiment report
• STL-style improvement

Version history

• alpha (Dec. 20, 2018)
• beta (Dec. 21, 2018)
  • Due to the poor initial design, cancelled the usage of const_iterator that incurred the conflicts of various const
  • Completed the dynamic memory management under multiple layers of nested data structures
  • Added Member types into README
  • Initially tested the interfaces and fixed some bugs
• released! (Jan. 5, 2019)
• v1.0 (Jan. 5, 2019)
  • Systematically tested RedBlackTree
  • Tested all interfaces of SimpleMap
  • Fixed SimpleMap::count()
  • Fixed SimpleMap::iterator::operator++()