Updated README with more detailed descriptions of items

README.md

@@ -1,6 +1,6 @@
 # NP Library
 
-A utility c library demonstrating various data structures and algorithms.
+A utility C library of various data structures and algorithms.
 
 ## Building
 
@@ -18,40 +18,117 @@ Builds `src/libnplib.so` then builds and runs a C-Unit based test program in
 
 ## Data Structures
 
-### np_linkedlist
+### Singly Linked List
 
-np_linkedlist is a singly linked list. The source is located:
+The singly [linked list][1] implementation `np_linkedlist` is found at:
 
      src/np_linkedlist.h
      src/np_linkedlist.c
 
+[1]: http://en.wikipedia.org/wiki/Linked_list
+
+#### Operations
+
+* __push__ - add an item to the front of the list
+* __pop__ - remove the first item in the list
+* __reverse__ - reverse order of items in the list
+* __length__ - determine the length of the list
+* __add__ - add an item at a particular location in the list
+* __remove__ - remove an item at a particular location in the list
+* __get__ - get an item at a particular location in the list
+* __iterator__ - an iterator to iterate over items in the list
+
 See `test/np_linkedlist_test.c` for sample usage.
 
-### np_arraylist
+#### Performance
+
+Push and pop operate at the head of the list in constant O(1) time. Add,
+remove, and get operate in _search time_ + O(1) time. Searching for an item
+by index is a O(i) operation where i is target index. Length and reverse
+operate in O(n) linear time. The entire list is traversed to determine its
+length or to reverse the list.
+
+The extra space required by the list is linear O(n) relative to the size of
+the list.
+
+### Array List
 
-np_arraylist is a dynamic array. The source is located:
+The array list (or [dynamic array][2]) implementation `np_arraylist` is found
+at:
 
      src/np_arraylist.h
      src/np_arraylist.c
 
+[2]:http://en.wikipedia.org/wiki/Dynamic_array
+
+#### Operations
+
+* __push__ - add an item to the front of the list
+* __pop__ - remove the first item in the list
+* __reverse__ - reverses the order of items in the list
+* __length__ - determine the length of the list
+* __add__ - add an item at a particular location in the list
+* __remove__ - remove an item at a particular location from the list
+* __get__ - get an item at a particular location in the list
+* __iterator__ - an iterator to iterate over items in the list
+
 See `test/np_arraylist_test.c` for sample usage.
 
-### np_hashmap
+#### Performance
+
+Push and pop operate at the head of the list in linear O(n) time. Inserting
+or removing list items requires moving all items after the target item in
+the list. Add and remove operate generally at linear O(n) time. Adding or
+removing at the end of the list is constant O(n) time (amoritized). Get and
+length operate in constant O(1) time. Reverse operates in linear O(n) time.
+
+The extra space required by the list is linear O(n) relative to the size
+of the list.
+
+### Hash Map
 
-np_hashmap implements a hash based map (hashtable). Hash collisions are
-resolved with chaining. The source is located:
+The hash map (or [hash table][3]) implementation `np_hashmap` is found at:
 
      src/np_hashmap.h
      src/np_hashmap.c
 
+[3]:http://en.wikipedia.org/wiki/Hash_table
+
+#### Operations
+
+* __put__ - associates the given value with the specified key
+* __get__ - gets the item associated with the given key
+* __remove__ - removes the given key and its assocated value
+
 See `test/np_hashmap_test.c` for sample usage.
 
-### np_treemap
+#### Performance
+
+Insert and get operate on average in O(1 + n/k) time and linear O(n) time
+in the worst case. Put is constant O(1) in time.
+
+The extra space required by the map is linear O(n) relative to the number
+of items in the map.
+
+### Tree Map
 
-np_treemap is a red-black tree based sorted map. The map provides ordering
-on the keys based upon a given comparator function. The source is located:
+The tree map implementation `np_treemap` is found at:
 
      src/np_treemap.h
      src/np_treemap.c
 
+#### Operations
+
+* __put__ - associates the given value with the specified key
+* __get__ - gets the item associated with the given key
+* __remove__ - removes the given key and its assocated value
+* __iterator__ - iterate over map keys in key order
+
 See `test/np_treemap_test.c` for sample usage.
+
+#### Performance
+
+Put, get, and remove operate in logarithmic O(log n) time.
+
+The extra space required by the map is linear O(n) relative to the number
+of items in the map.