1. Different styles of algorithms: batch-style: avg of A[N], space intensive not proper on-line: space O(1), constant # of space in-place: O(1), data stream proc identify missing id in 1 to N-k 2 << N missing on-the-fly average N-1

2. Special natures: documents/comments/notes coder: coding phase== software engineer: coder, analyst, designer, tester, customer service, Readme writer tester == verification engineer Software products: bespoke: specialized system, ccny lib control generic: office excel, word, big idea Software system attributes: define goodness, quality measure of system: apple is popular?? GUI-user friendly Understandable: to other programmer efficiency, reliability: supposed to do, robustness: no serious crash, defensive prog: try catch portability: OS: jvm javac/java, C/C++: most

3. CASE: smart editor: matlab editor, version control: git(linux), make ( ver1, ver1.01, ver1.02…..ver8.01 ver8.02 Diff: unix/linux command current version, keep deltas, collaborate Software engineers!= coders, analyst, designer, verification eng. writers 3 Subjects/parties: clients $; dev: O; end-users/customers Software development process: life-cycle models: many choices tools: PL(matlab, python, R, java, C#, Ruby), DB, OS, IDE/CASE; personnel. Intelligence: moving target? 88/4Turing’s test Life cycle: series of steps thru which the development progresses.

4. Water-fall: traditional, mostly used, ord eng. req analysis (>30%): specification; needs/constraints/$$/deadline/reliability/size investigation: concept exploration, meetings, feasibility, finance 30 cities, travel once minimal $$ 30!: Hamilton circle, NP-complete approximate RSA: public-key, NP: factor 35 45e84ee984: 6month Hard question can be our friends, not always our foes mutual misunderstanding: replace(put it back) the handle in gas station; “I have a lamb”: I have a lamb. 1 food; 2: pet; 3: nice husband/guy solutions: 1. use logic description, math: universal language 2. diagram/graph/visualization tools; 3. prototype: simulation sw/hw, simulink, python/matlab prototyping pl, sql