This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Analysis of Algorithms Mariusz Bajger COMP2781/8781 School of Computer Science, Engineering and Mathematics May 6, 2011 1/21 Reading and Exercises Reading Epp, Chapter 11 Exercises Sec. 11.1 (use as much as you need; revision of MATH1121), 11.2 (blue ones), 11.3 (Ex.135), 11.4 (in blue), 11.5 (Ex. 125) Good learning strategy: BE ACTIVE! I Regularly revise lectures I Solve the suggested exercises I Be critical when reading textbook/lectures I Ask your colleagues, ask the lecturer, dont be shy! I It is OK to ask for help any time 2/21 Algorithm Characteristics (1) Input (2) Output (3) Precise steps (4) Determinism or randomness (5) Finiteness or constant run (6) Correctness (7) Generality An algorithm is a finite sequence of clearly and unambiguously defined steps for performing a task. Each step must be executable in a finite time and the whole process must be guaranteed to stop after a finite number of steps. 3/21 Time Efficiency (never mind, just wait a few years) I Often the running time depends on the problem size . I Problem size = size of the input or the value of a commandline argument. I 3 Ghz processor performs up to 3 bilion operations per second, that is, one operation approx. takes up to 0.3 nanoseconds. 4/21 Input size vs time efficiency I To approximate running time we need: (1) good understanding of the program (algorithm) (2) some mathematical analysis tools (3) understanding of the system and the computer I Combination of some empirical observations and small set of mathematical tools is usually sucient to approximate well the running time for most algorithms. I Doubling hypothesis is a practical quick method of estimating the input size and runtime relationship: Run the program several times doubling the input each time ....
View
Full
Document
This note was uploaded on 06/12/2011 for the course MATH 103 taught by Professor Wouters during the Spring '08 term at Wisc Oshkosh.
 Spring '08
 WOUTERS
 Math, Algebra

Click to edit the document details