一个google面试的准备清单

  

Data Structures

   1. Integer
     – find number of 1s
     – next largest smaller
     – smallest larger number
     – determine if is palindrom
     – itoa, atoi
     – add 2 numbers w/o using + or arithmetic operators
     – implement *, -, / using only +
     – find max of two numbers w/o comparison
     – swap two numbers with +/-
     – swap two numbers with ^
     – given an integer, find the closest number that ispalindrome
     – implement putlong() by putchar()
   2. Bit array
   3. Linked list
     – find cycle,
     – find position of cycle starts
     – reverse LL
     – delete a node in middle
     – each node contains a value pointer pointing to anode, 
       duplicate LL.
     – remove duplicates from sorted/un-sorted LL.
     – find n-th to last node to end
     – number is represented by LL, add 2 numbers
   4. Array
     – Longest common substring (LCSubstr)
     – Longest common subsequence (LCS).
     – Longest increasing subsequence (LIS).
     – Longest palingdrome in string.
     – array, elements are +/-, find subsequence of max sum
     – circular array, elements are +/-, find subsequence of maxsum
     – find all pairs of integers add up to a sum
     – find all pairs of integers add up to asum, 
       integers are +/- and sorted
     – find one missing number in N numbers in range [0, N]
     – find two missing number in N numbers in range [0, N].
     – binary search circular array
     – Given {a1, a2, a3, ..}, {b1, b2, b3, …}, 
       get {a1, b1, a2, b2, …}
     – Given 2 arrays A and B, A large enough to holdboth, 
       merge B into A.
   5. String
     – KMP, Rabin-Karp, Boyer Moore
     – reverse string
     – reverse words in string  
     – strcpy, strcmp, strstr, atoi, itoa, strdup
     – remove duplicate characters in O(1) space
     – Given dictionary, transform one word to another of samelength.
     – Given large text, find min cover distance of n words.
     – find longest word made of other words
     – find first non-repeated char
     – remove specified char from a string
   6. Matrix
     – matrix elements are +/-, find submatrix of max sum
     – rotate a matrix by 90 degrees
     – each cell is black/white, find max subsquare with blackborder.
     – binary matrix, find largest square matrix with 1s
     – binary matrix, find largest rectangle matrix with1s 
   7. Stack
     – implement stack by queue.
     – augmented stack with O(1) push, pop, min
     – use single array to implement 3 stacks
     – sort a stack in ascending order usingonly 
       push/pop/top/isEmpty/isFull
   8. Queue
     – implement queue by 2 stacks
   9. Priority Queue
  10. Heap
     – create heap on array
  11. Young Tableau
     – find element
     – get k-th element
  12. BST
     – pre/in/post-order traversal, recursive and iterative
     – pre/in/post-order traversal, recursive anditerative, 
       with parent pointer
     – find height
     – determine IsBST
     – find "next" node of a given node in inorder sequence
     – find k-th inorder element
     – find range of elements
     – find diameter
     – find all path adding to a sum
     – Check if a tree is balanced
     – Convert sorted array into balanced BST
     – Find first common ancestor of two nodes in a BT or BST
     – Link each node to its right sibling
     – Print by level (BFS)
     – Print by level (BFS) in reverse order
     – Determine if 2 BSTs have the same structure
     – Create a mirror BT of a BT
     – Replicate a linked structure
  13. 2-3-4 Tree
  14. Red-Black Tree
  15. Splay Tree
  16. AVL Tree
  17. Trie
  18. Suffix Array
  19. SuffixTree  
     – LCSubstr (longest common substring)
     – Longest repeated substring
     – longest palindrome
     – substring search
     – data compression
  20. B-Tree
  21. KD Tree
  22. Range Tree
  23. Hash Table
  24. Bloom filter
  25. Disjoint set
  26. Graph
     – DFS, BFS
     – find path existence between two nodes
     – Min vertice set covering all edges
     – shortest path
     – minimum spanning tree
     – min edge coverage by vertex

Sorting

   1. Bubble sort
   2. Insertion sort
   3. Selection sort
   4. Shell sort
   5. Heap sort
   6. Quicksort 
   7. Mergesort 
   8. N-way merge sort (externalsort)
   9. Counting sort
  10. Bucket sort

Search

   1. Linear search
   2. Binary search
     – Binary search, iterative/recursive 
     – find missing number is sorted array 
     – search in circular sorted array 
   3. Quick Select

Dynamic programming

   1. BST
   2. COV 
   3. ILP 
   4. KS 
   5. LCS 
   6. LSP 
   7. MCM 
   8. ODP 
   9. SCP 
  10. SPA
  11. SPC
  12. TSP 
  13. Given array a[], when i < j,get max(a[i] – a[j]).
  14. levenshtein edit distance
  15. Coin Change problem.

Large-scale system

   1. Bloom filter
   2. Bit-array/bit-map
   3. Heap
   4. Hash table
     – d-left hashing
   5. Sub-division
   6. Database indexing
   7. Inverted index
   8. External sort
   9. Map-reduce

Discrete math, Probability and Statistics, NumericalComputation

   1. Permutation
     – 3 colors, how many ways to color a cube?
     – robot, ways to go to diagonal corner on NxN matrix?
     – print all combinations of valid n-pairs of parentheses
     – print all subsets of a set
   2. Combination
   3. Sampling
   4. Random numbergenerator
     – What’s a good random number generator?
     – Given random generator [1, 2, 3, 4, 5], 
       generate random in [1..7].
   5. Reservoir sampling
   6. Find median in stream
   7. Card shuffling
   8. Primality testing
   9. Find prime numbers: naive,sieve of Eratosthenes, sieve of Atkin
  10. Randomized primality testing, what’s goodrandom generator
  11. Fibonacci sequence 
  12. Factorial numbers
  13. Frobenous numbers
  14. Newton-Ralphson algorithm
  15. Bayes theorem

Computational algebra

   1. Convex-hull
   2. Closest pairs

Computational theory

   1. Automata theory
   2. DFA
   3. NFA
   4. Regular language
   5. Pumping lemma
   6. Turing machine
   7. NP-completeness
        1. TSP
        2. Vertex-cover problem
        3. Set-covering problem.
        4. Subset-sum problem.

OS

   1. Process and thread
   2. Semaphore, mutex,monitor
   3. Function call/callframe
   4. Context switch
   5. Multi-threading
   6. Multi-process
   7. Thread safety
   8. Big/Little-endian
   9. Heap/stack
  10. Malloc/free
  11. Virtual memory, page fault, thrashing
  12. DMA (Direct Memory Access)

Networking

   1. 7-layer OSI model
   2. 4-layer TCP/UDP model
   3. TCP/UDP
   4. TCP 3-way handshake (ACKmachanism), 
     flow control, congestion control
   5. Things happen afterentering url
   6. Routing protocols: BGP,OSPF, RIP
   7. Subnet mask, packet routingon same/different network.
   8. Performance