CSCI 4041: Algorithms and Data Structures

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CSCI 4041 Algorithms and Data Structures

• Instructor
• Mohamed Mokbel (mokbel_at_cs.umn.edu)

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Welcome to CSCI 4041

• Your Host Mohamed F. Mokbel
• Office EE/CS 4-207
• Web www.cs.umn.edu/mokbel
• Email mokbel_at_cs.umn.edu
• (Include CSCI4041 on the Subject line)
• Office Hours Tue, Thu 1230 PM 130 PM (or
  by appointment)
• TA Daa-hey Woo
• Email dwoo_at_cs.umn.edu
• Office hours Tue, Thu, 1000 AM 1100 AM
• Ted Kaminski
• Email edinski_at_cs.umn.edu
• Office hours TBD

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Welcome to CSCI 4041

• Text Book
• Introduction to Algorithms (Second Edition)
• ISBN 0-07-013151-1
• Thomas Cormen, Charles Leisrson, Ronald Rivest,
  Clifford Stein
• Book website www.introductiontoalgorithms.com
  Chapters 1, 2, 3, 4, 6, 7, 8, 10, 11, 12, 15,
  16, 18, 19, 21, 22, 23, 24, 35

• Class web page
• http//www-users.itlabs.umn.edu/classes/Fall-2008/
  csci4041/
• Tentative schedule is in the course web site
• Stay tuned for announcements, labs, homeworks,
  and grades

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Grading Policy

• Final Exam (25) Inclusive
• Two Midterm Exams (25) Second midterm will
  cover only the topics presented after the first
  midterm.
• Homeworks and Programming assignments (5 to 7)
  50.
• No late submission is accepted. Only justified
  serious circumstances (e.g., medical reasons) can
  be accommodated.
• Collaboration in homeworks Discussion is
  allowed, yet, please write your own solution
• Collaboration in Exams Not allowed.

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Topics To be Covered

• PART I Foundations (Chapters 1 4)
• Why we are studying algorithms.
• How do we measure the efficiency of an algorithm
• Getting the sense of a good/bad algorithm
• PART II Sorting (Chapters 6 8)
• Why we need sorting.
• Why do we need to study various algorithms for
  sorting
• Which algorithm to use at which scenario

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Topics To be Covered

• PART III Data Structures (Chapters 10 12)
• Stacks, queues, linked list, hash tables, tree
  structures
• Main functionalities Insertion, deletion,
  updating, and searching
• Which data structure to use at which scenario
• PART IV Advanced Design and Analysis Technique
  (Chapters 16, 17)
• Greedy Algorithms
• Dynamic Programming

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Topics To be Covered

• PART V Advanced Data Structures (Chapters 18,
  19, 21)
• B-trees, Heaps, Disjoint Sets
• Main functionalities Insertion, deletion,
  updating, and searching
• Which data structure to use at which scenario
• PART VI Graph Algorithms (Chapters 22-25)
• Problems that can be represented as graphs
• Searching/traversing a graph
• Shortest path algorithms
• Minimum spanning trees

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Why we need to study Algorithms

• Performance
• Performance is a crucial part of software design
• What other factors that could be more important
  than performance?
• Programming Skills

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Sorting Algorithms

• Sorting is one of the classical problems where
  there are dozens of algorithms to solve
• Input A set of numbers a1, a2, .an
• Output A permutation of the input set a1, a2,
  .an where a1 lt a2lt .lt an
• Example Sort the sequence 5, 2, 4, 6, 1, 3
• What affects the performance of the sorting
  algorithm?

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Algorithm Efficiency

• Insertion Sort
• Average analysis O(N2) ? c1N2
• Merge Sort
• Average analysis O(N Log2 N) ? c2 N Log2 N
• Average analysis of an algorithm is the dominant
  factor regardless of the constants and computer
  power.
• Example Sort 106 keys with Computer A (109
  instructions/sec, insertion sort with c12) Vs
  Computer B (107 instructions/sec, merge sort with
  c250)