1 Data Structure
 1.1 Question lists
 1.2 Basic Knowledge
 1.3 Array
  1.3.1 Application
 1.4 Linked list
  1.4.1 Basic
  1.4.2 Operations
  1.4.3 Application
   Bucket sort
   Radix sort
   Online Equivalence class
   Offline Equivalence class
   Other interview questions
 1.5 Matrix
   sparse matrix
 1.6 Stack
  1.6.1 Application of Stack
 1.7 Queue
  1.7.1 Circule Queue
  1.7.2 Application of queue
 1.8 Heap
   application
 1.9 Tree
  1.9.1 Search Tree
  1.9.2 Tree and recursion
  1.9.3 Application
 1.10 Graph
  1.10.1 Basic
  1.10.2 DFS and BFS
   DFS
   BFS
  1.10.3 spanning tree
  1.10.4 Application
2 Algorithm
 2.1 Math and geometry basic
  2.1.1 geometry
   convex hull
  2.1.2 Permutation and combination
  2.1.3 solution space
  2.1.4 Usage of model %
 2.2 Recursive
 2.3 Sort
  2.3.1 Simple sort
  2.3.2 quick sort
  2.3.3 Bucket and radix sort
 2.4 Greedy
  2.4.1 application
 2.5 Divide Conquer
 2.6 Dynamic programming
 2.7 backtracing and branch and bound