Tuesday, 11/9/99

• Exam#2 review
  • generally result
  • distribution and interpretation
  • ideas for problem solving
  • sample solution e2.c
  • discussions
• prime factors (e#2-p#2)
  • key idea: unique factor?
  • formatted output: first and last?
  • efficiency: modified from prime factorization program
  • simple program going up with numbers and checking with IsPrime()
  • simple but much less efficient
• flag drawing (e#2-p#4): common problem: off center circle
• personal name (e#2-p#4):
  • two parts
  • deal as one set of conditions (sample solution)
  • better yet: same function for first and last name
• hw#10 questions?

Thursday, 11/11/99

• hw#10 questions?
• two key elements to programs: algorithm + data structure
• simple vs. compound data types
• more (advanced) algorithms
• Knuth book: data structure, numerical algorithm, searching and sorting
• compound data types
  • Excel assignment (#6) example
  • collection of data, treat as one entity
  • storage and computation on them
  • statistics example: average, median, std. dev., etc.
  • intermediate results: e.g., factorial for combinations
  • lists, tables, etc.: general database
• array vs. other structured data (list, record, etc.)
• arrays
  • ordered: access by index
  • homogeneous: same type for each element
  • to specify: element type and size
  • declaration: e.g., int exam1_score[CSE1341_802_CLASS_SIZE];
  • index: start with 0
    - work with conventional start of 1
    - index range shift
    - skip item with index 0
  • selection: exam1_score[i]
  • statistics example: variance and std. dev
  • operates on individual elements in C not an array as a whole
• computation with arrays
• mostly numerical/scientific computations
• sketches for some computations (statistics, etc.)

Tuesday, 11/16/98

• array usage: declaration, initialization, access, as parameters
• array initialization
  • at declaration, small arrays
  • implicit size with initialization at declaration
    - A[] = {....}
  • loops for initialization
    - read from user input in gymjudge.c
    - more common: read from data file
    - real-time/control systems: sensor input
• computation with arrays
  • examples: gymjudge.c,
  • simple search with array: findcoin.c (from ch.12)
  • sorting and advantage of sorted data: median, fast search, etc
  • (intermediate) results to avoid repeated computation
  • statistics: variance and std. dev, modified gymjudge.c
• strings as special case of arrays
• arrays as parameters
  • caller: array name
  • number of elements in the array
  • allocated size vs. effective size
  • example calls with array name and array size
    - ret_type funcA(a_type A[MaxSize], int actual_size);
    - ret_type funcB(a_type A[], int actual_size);
    - ret_type funcC(a_type *A, int actual_size);
    - 2nd way preferred (less chance for confusion)
  • example: findcoin.c
  • combination with other parameters: FindIntegerInArray() in findcoin.c
  • mechanism: aliasing
• hw#11

Thursday, 11/18/99

• questions about hw#11?
• more array example: from swap to reverse.c
  • swap two values in a program: need for temp var
  • functional implementation: need for pointers
  • array implementation: any two elements
  • generalization: reverse.c
• strings: char string[N]; (Chapter 14)
• representation and storage
• standard I/O for strings (Chapter 15)
  • scanf()/printf() -- standard input function
  • use of pointers in scanf()
    -- scanf("%d", &n)
    -- see Table 15-1 (p.541)
  • scanf("%s", strN) and printf("%s", strN); for "char strN[N]"
  • examples from strlib.h and strlib.c in Appendix B
  • space character handling
  • %s and GetLine() comparison
  • [xyz] and [^xyz]
  • e.g., to read a whole line, use: scanf("[^\n]", line);
• string as arrays in computation
  • elements: char, use ctype.h
  • example: acronym.c
  • character by character processing
• string operations (Chapter 14)
  • ANSI string library: string.h (Table 14-1, p.503)
  • specifically: strcpy(), strcat(), strlen(), strcmp(), .....
• optional homework: hw#12
  • 20 bonus points
  • keywords storage in program, see example in findcoin.c (ch.12)
  • search and compare to keywords using "string.h" function "strcmp()" etc.
  • sorting as you read things in or sorting at the end

Tuesday, 11/23/99

• more about strings (Chapter 14 and 9)
  • ANSI string library: string.h (Table 14-1, p.503)
  • specifically: strcpy(), strcat(), strlen(), strcmp(), .....
  • strlib.h/chapter 9 for our text
  • example: linelen.c
  • examples: ncopies.c
• a more comprehensive example
  • palindrome.c
  • definition and general idea
  • implementation using reverse and strcmp()
  • generalization:
    - skipping over non-letter character
    - case-insensitive comparison
  • loop control/exiting conditions
• hw#12
  • basic string operations: string.h functions
  • searching by one-by-one comparison:
    - similar to FindIntegerInArray() (in findcoin.c, ch.12)
    - but use strcmp()
  • ideas for sorting: insert (during) vs. select (after)
  • insertion sort: find the right place, insert, and move the rest
  • moving/swapping for strings: strcpy
  • idea same for individual (numerical) elements
• final exam: Sat. 12/11, 8-11am, select 2 hour slot
• course evaluation?

Thursday, 11/25/99

• Happy Thanksgiving! (no class)

Tuesday, 11/30/99

• more questions about hw#12
• multidimensional arrays
  • array: homogeneous elements -> array as element
  • 2-d array: matrix (or commonly used tables)
  • memory layout and access
  • ideas about bit, byte, word, etc.
  • initialization: at declaration, init loop/function
  • example: symmetry.c
  • other examples
  • higher dimensional arrays, 3-d and up
  • n-d arrays as parameters: need to specify all dimension sizes except 1st (1st optional)
  • reason: indexing and accessing
  • n-d array as (static) global variables
• information units
  • bit: binary digit
  • byte: 8 bits
  • word: n bytes, typically n=1, 2, 4, 8...
  • memory address: word addressable (some byte addressable)
• final exam information

Thursday, 12/2/99

• character/string as multidimensional arrays: palindrome.c
• introduction to sorting
  • advantage of sorted data
  • data structure and sorting: array, (and list, tree, etc.)
  • ideas about sorting:
    • insertion sort idea for hw#12,
    • selection sort
    • other sorting algorithms: bubble, quick, etc.
  • efficiency: time and space
  • selection sort example in "sort.c" (Fig. 12-5, pp.443-444)
• searching of sorted data and homework#12:
  • one-by-one comparison: search keyword list
    - similar to FindIntegerInArray() (in findcoin.c, ch.12)
  • sorted data: binary search idea
  • hw#12 partial solution: particularly IsKeywordB() in
  • validB.c
  • efficiency O(log(n)) instead of O(n)
  • binary trees and B-trees, and indexing hierarchies/files
• review for final
  • topics covered: on-line list
  • general info: see final exam information
  • major topics/programming:
    1. arrays
    2. strings,
    3. searching/sorting
  • other things: multiple choice and short answer
  • office hours for the next week:
    - open office
    - early afternoons best time to see me

Saturday, 12/11/99

• 9-11am, final exam: See online information