Added notes about pointer-to-pointer.

plan.txt

@@ -175,7 +175,7 @@ Then test it out on a computer to make sure it's not buggy from syntax.
     * - Space
         - contiguous in memory, so proximity helps performance
         - space needed = (array capacity, which is >= n) * size of item, but even if 2n, still O(n)
-Linked Lists
+* - Linked Lists
     * - Description:
         * - https://www.coursera.org/learn/data-structures/lecture/kHhgK/singly-linked-lists
         * - Lynda.com:
@@ -187,7 +187,11 @@ Linked Lists
         - not the whole video, just portions about Node struct and memory allocation.
     * - why you should avoid linked lists:
         - https://www.youtube.com/watch?v=YQs6IC-vgmo
-    - implement (with tail pointer):
+    * - Gotcha: you need pointer to pointer knowledge:
+        (for when you pass a pointer to a function that may change the address where that pointer points)
+        This page is just to get a grasp on ptr to ptr. I don't recommend this list traversal style. Readability and maintainability suffer due to cleverness.
+        - https://www.eskimo.com/~scs/cclass/int/sx8.html
+    * - implement (with tail pointer):
         * - size() - returns number of data elements in list
         * - empty() - bool returns true if empty
         * - front() - get value of front item
@@ -199,11 +203,10 @@ Linked Lists
         * - value_at(index) - returns the value of the nth item
         * - insert(index, value) - insert value at index, so current item at that index is pointed to by next at index
         * - erase(index) - removes node at given index
-        - value_n_from_end(n) - returns the value of the node at nth position from the end of the list
-        - reverse() - reverses the list
-        - remove(value) - remove all elements with this value
-        - find(value) - return pointer to the node that has this value
-    Doubly-linked List
+        * - value_n_from_end(n) - returns the value of the node at nth position from the end of the list
+        * - reverse() - reverses the list
+        * - remove(value) - removes the first item in the list with this value
+    * - Doubly-linked List
         - Description: https://www.coursera.org/learn/data-structures/lecture/jpGKD/doubly-linked-lists
         - No need to implement
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