Couple basic structures:

• Arrays (mostly for searching and sorting)
• Singly Linked List (sll)
• Binary Sort Tree (bst)
• Binary Heap Array (bha)
• Hash Table as Arrays (hta)
• Trees
• Graphs

Couple basic algorithms:

• Add/Insert
• Delete/Remove (also remove at...)
• Print/Traverse
• Pre-order tree traversal
• Find/Search (also find at...)
• Linear search (x2)
• Sort/Order
• Bubble sort
• Insert sort
• Selection sort
• Merge sort
• Quick sort
• Heap sort (x2)
• Binary search tree sort

Some string operations:

• String to number

Machine Learning:

• kNN data probing

Check memory leaks:

valgrind --tool=memcheck --leak-check=yes example1

Compile C for use in R:

R CMD SHLIB -o mylib.so a.f b.f -L/opt/acml3.5.0/gnu64/lib -lacml