{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

lec14a - CS C341 I S C361 Data Structures Algorithms...

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style 2/7/11 Sundar B. CSIS, BITS, Pilani CS C341 / I S C361 Data Structures & Algorithms Dictionary Data Structures - Hashing Bloom Filters - Motivation - Implementation - Analysis - General Scenario - Applications. Las Vegas vs. Monte Carlo Techniques 11
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2/7/11 Sundar B. CSIS, BITS, Pilani Bloom Filters - Motivation Consider this outline for stemming : for each word w if (w is an exception word) then getStem(w,D) else apply-simple-rule(w) Cost for checking exceptions: N * Td where N is # words and Td is lookup time (on disk) 22 Need dictionary lookup on disk
Image of page 2
2/7/11 Sundar B. CSIS, BITS, Pilani Bloom Filters - Motivation Suppose we can trade-off space for false positives (in lookup): for each word w if (w is in Dm ) // in-memory lookup (probabilistic) then { s = getStem(w, Dd) // disk lookup (deterministic) if invalid(s) then apply-simple-rule(w); } else { apply-simple-rule(w); } Cost for checking exceptions: N * Tm + (r + f )*N*Td 33
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2/7/11 Sundar B. CSIS, BITS, Pilani Bloom Filters – An implementation Hash table is an array of bits indexed from 0 to m-1.
Image of page 4
Image of page 5
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern