Hardware/Software Co-Design

Size: px
Start display at page:

Download "Hardware/Software Co-Design"

Transcription

1 1 / 45 Hardware/Software Co-Design Parallel Patterns III Miaoqing Huang University of Arkansas Fall 2011

2 2 / 45 Outline 1 2

3 3 / 45 Outline 1 2

4 What is segmented scan? Scan + Barriers/Flags associated with certain positions in the input arrays Operations do not propagate beyond barriers Value Flag Output / 45

5 What is segmented scan? Scan + Barriers/Flags associated with certain positions in the input arrays Operations do not propagate beyond barriers Value Flag Output How to deal with it? 5 / 45

6 What is segmented scan? Scan + Barriers/Flags associated with certain positions in the input arrays Operations do not propagate beyond barriers Value Flag Output How to deal with it? Deal with the segments one by one 6 / 45

7 What is segmented scan? Scan + Barriers/Flags associated with certain positions in the input arrays Operations do not propagate beyond barriers Value Flag Output How to deal with it? Deal with the segments one by one Do many scans at once, no matter their sizes 7 / 45

8 Example (of the Naive Approach) Value Flag / 45

9 Example (of the Naive Approach) Value Flag Value Flag / 45

10 Example (of the Naive Approach) Value Flag Value Flag Value Flag / 45

11 Example (of the Naive Approach) Value Flag Value Flag Value Flag Value Flag / 45

12 Example (of the Naive Approach) Value Flag Value Flag Value Flag Value Flag Value Flag / 45

13 Pseudo Code (of the Naive Approach) //x[]: value; f[]: flag for d = 0 to log(n) - 1 do forall k in parallel do if k>=2^d then if f[k] is NOT set then x[out][k] = x[in][k-2^d] + x[in][k] f[out][k] = f[in][k-2^d] f[in][k] else x[out][k] = x[in][k] f[out][k] = f[in][k] else x[out][k] = x[in][k] f[out][k] = f[in][k] swap(in,out) 13 / 45

14 Pseudo Code (of the Naive Approach) //x[]: value; f[]: flag for d = 0 to log(n) - 1 do forall k in parallel do if k>=2^d then if f[k] is NOT set then x[out][k] = x[in][k-2^d] + x[in][k] f[out][k] = f[in][k-2^d] f[in][k] else x[out][k] = x[in][k] f[out][k] = f[in][k] else x[out][k] = x[in][k] f[out][k] = f[in][k] swap(in,out) Work-efficient implementation See Scan Primitives for GPU Computing by Sengupta, Harris, Zhang, and Owens 14 / 45

15 15 / 45 Outline 1 2

16 16 / 45 Sort Useful for almost everything Optimized versions for the GPU already exist Two examples Radix sort Quick sort

17 Radix Sort Definition Sort integers by processing individual digits, by comparing individual digits sharing the same significant position Least Significant Digit (LSD) radix sort 1 Take the least significant digit (or group of bits, both being examples of radices) of each key 2 Group the keys based on that digit, but otherwise keep the original order of keys 3 Repeat the grouping process with each more significant digit 17 / 45

18 18 / 45 Radix Sort Example original list

19 19 / 45 Radix Sort Example original list

20 20 / 45 Radix Sort Example original list 1s place

21 21 / 45 Radix Sort Example original list 1s place

22 22 / 45 Radix Sort Example original list 1s place 10s place

23 23 / 45 Radix Sort Example original list 1s place 10s place

24 24 / 45 Radix Sort Example original list 1s place 10s place 100s place

25 25 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

26 26 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

27 27 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

28 28 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

29 29 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

30 30 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

31 31 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

32 32 / 45 Radix Sort on GPU Integers are represented in radix-2 format on computer Split can be used for radix sort

33 33 / 45 Quick Sort Quick sort sorts by employing a divide and conquer strategy to divide a list into two sub-lists Steps 1 Pick an element, called a pivot, from the list 2 Reorder the list so that all elements with values less than the pivot come before the pivot, while all elements with values greater than the pivot come after it (equal values can go either way) After this partitioning, the pivot is in its final position 3 Recursively sort the sub-list of lesser elements and the sub-list of greater elements

34 34 / 45 Quick Sort Quick sort sorts by employing a divide and conquer strategy to divide a list into two sub-lists Steps 1 Pick an element, called a pivot, from the list 2 Reorder the list so that all elements with values less than the pivot come before the pivot, while all elements with values greater than the pivot come after it (equal values can go either way) After this partitioning, the pivot is in its final position 3 Recursively sort the sub-list of lesser elements and the sub-list of greater elements Example is given at the chalkboard

35 35 / 45 Quick Sort on GPU Use segmented scan and split

36 36 / 45 Quick Sort on GPU Use segmented scan and split

37 37 / 45 Quick Sort on GPU Use segmented scan and split

38 38 / 45 Quick Sort on GPU Use segmented scan and split

39 39 / 45 Quick Sort on GPU Use segmented scan and split

40 40 / 45 Quick Sort on GPU Use segmented scan and split

41 41 / 45 Quick Sort on GPU Use segmented scan and split

42 42 / 45 Quick Sort on GPU Use segmented scan and split

43 43 / 45 Quick Sort on GPU Use segmented scan and split

44 44 / 45 Quick Sort on GPU Use segmented scan and split

45 45 / 45 Quick Sort on GPU Use segmented scan and split

46 46 / 45 Lab-6 Preview for (m=0; m<m; m++) { phimag[m] = rphi[m]*rphi[m] + iphi[m]*iphi[m]; for (n=0; n<n; n++) { expq = 2*PI*(kx[m]*x[n]+ky[m]*y[n]+kz[m]*z[n]); } } rq[n] += phimag[m]*cos(expq); iq[n] += phimag[m]*sin(expq);

Data Structures and Algorithms

Data Structures and Algorithms Data Structures and Algorithms Spring 2017-2018 Outline 1 Sorting Algorithms (contd.) Outline Sorting Algorithms (contd.) 1 Sorting Algorithms (contd.) Analysis of Quicksort Time to sort array of length

More information

Recap: Prefix Sums. Given A: set of n integers Find B: prefix sums 1 / 86

Recap: Prefix Sums. Given A: set of n integers Find B: prefix sums 1 / 86 Recap: Prefix Sums Given : set of n integers Find B: prefix sums : 3 1 1 7 2 5 9 2 4 3 3 B: 3 4 5 12 14 19 28 30 34 37 40 1 / 86 Recap: Parallel Prefix Sums Recursive algorithm Recursively computes sums

More information

b + O(n d ) where a 1, b > 1, then O(n d log n) if a = b d d ) if a < b d O(n log b a ) if a > b d

b + O(n d ) where a 1, b > 1, then O(n d log n) if a = b d d ) if a < b d O(n log b a ) if a > b d CS161, Lecture 4 Median, Selection, and the Substitution Method Scribe: Albert Chen and Juliana Cook (2015), Sam Kim (2016), Gregory Valiant (2017) Date: January 23, 2017 1 Introduction Last lecture, we

More information

CS 1110: Introduction to Computing Using Python Sequence Algorithms

CS 1110: Introduction to Computing Using Python Sequence Algorithms CS 1110: Introduction to Computing Using Python Lecture 22 Sequence Algorithms [Andersen, Gries, Lee, Marschner, Van Loan, White] Final Exam: Announcements May 18 th, 9am-11:30am Location: Barton Hall

More information

Divide and conquer. Philip II of Macedon

Divide and conquer. Philip II of Macedon Divide and conquer Philip II of Macedon Divide and conquer 1) Divide your problem into subproblems 2) Solve the subproblems recursively, that is, run the same algorithm on the subproblems (when the subproblems

More information

Kartsuba s Algorithm and Linear Time Selection

Kartsuba s Algorithm and Linear Time Selection CS 374: Algorithms & Models of Computation, Fall 2015 Kartsuba s Algorithm and Linear Time Selection Lecture 09 September 22, 2015 Chandra & Manoj (UIUC) CS374 1 Fall 2015 1 / 32 Part I Fast Multiplication

More information

Randomized Sorting Algorithms Quick sort can be converted to a randomized algorithm by picking the pivot element randomly. In this case we can show th

Randomized Sorting Algorithms Quick sort can be converted to a randomized algorithm by picking the pivot element randomly. In this case we can show th CSE 3500 Algorithms and Complexity Fall 2016 Lecture 10: September 29, 2016 Quick sort: Average Run Time In the last lecture we started analyzing the expected run time of quick sort. Let X = k 1, k 2,...,

More information

Sorting and Searching. Tony Wong

Sorting and Searching. Tony Wong Tony Wong 2017-03-04 Sorting Sorting is the reordering of array elements into a specific order (usually ascending) For example, array a[0..8] consists of the final exam scores of the n = 9 students in

More information

CS483 Design and Analysis of Algorithms

CS483 Design and Analysis of Algorithms CS483 Design and Analysis of Algorithms Chapter 2 Divide and Conquer Algorithms Instructor: Fei Li lifei@cs.gmu.edu with subject: CS483 Office hours: Room 5326, Engineering Building, Thursday 4:30pm -

More information

Algorithms And Programming I. Lecture 5 Quicksort

Algorithms And Programming I. Lecture 5 Quicksort Algorithms And Programming I Lecture 5 Quicksort Quick Sort Partition set into two using randomly chosen pivot 88 31 25 52 14 98 62 30 23 79 14 31 2530 23 52 88 62 98 79 Quick Sort 14 31 2530 23 52 88

More information

CMPT 307 : Divide-and-Conqer (Study Guide) Should be read in conjunction with the text June 2, 2015

CMPT 307 : Divide-and-Conqer (Study Guide) Should be read in conjunction with the text June 2, 2015 CMPT 307 : Divide-and-Conqer (Study Guide) Should be read in conjunction with the text June 2, 2015 1 Introduction The divide-and-conquer strategy is a general paradigm for algorithm design. This strategy

More information

Design and Analysis of Algorithms PART II-- Median & Runtime Analysis Recorded by Chandrasekar Vijayarenu and Shridharan Muthu.

Design and Analysis of Algorithms PART II-- Median & Runtime Analysis Recorded by Chandrasekar Vijayarenu and Shridharan Muthu. Design and Analysis of Algorithms PART II-- Median & Runtime Analysis Recorded by Chandrasekar Vijayarenu and Shridharan Muthu. Medians and Order Statistics Minimum and maximum How many comparisons are

More information

Design and Analysis of Algorithms

Design and Analysis of Algorithms CSE 101, Winter 2018 Design and Analysis of Algorithms Lecture 4: Divide and Conquer (I) Class URL: http://vlsicad.ucsd.edu/courses/cse101-w18/ Divide and Conquer ( DQ ) First paradigm or framework DQ(S)

More information

CPS 616 DIVIDE-AND-CONQUER 6-1

CPS 616 DIVIDE-AND-CONQUER 6-1 CPS 616 DIVIDE-AND-CONQUER 6-1 DIVIDE-AND-CONQUER Approach 1. Divide instance of problem into two or more smaller instances 2. Solve smaller instances recursively 3. Obtain solution to original (larger)

More information

CS483 Design and Analysis of Algorithms

CS483 Design and Analysis of Algorithms CS483 Design and Analysis of Algorithms Lecture 6-8 Divide and Conquer Algorithms Instructor: Fei Li lifei@cs.gmu.edu with subject: CS483 Office hours: STII, Room 443, Friday 4:00pm - 6:00pm or by appointments

More information

Algorithms, Design and Analysis. Order of growth. Table 2.1. Big-oh. Asymptotic growth rate. Types of formulas for basic operation count

Algorithms, Design and Analysis. Order of growth. Table 2.1. Big-oh. Asymptotic growth rate. Types of formulas for basic operation count Types of formulas for basic operation count Exact formula e.g., C(n) = n(n-1)/2 Algorithms, Design and Analysis Big-Oh analysis, Brute Force, Divide and conquer intro Formula indicating order of growth

More information

1 Quick Sort LECTURE 7. OHSU/OGI (Winter 2009) ANALYSIS AND DESIGN OF ALGORITHMS

1 Quick Sort LECTURE 7. OHSU/OGI (Winter 2009) ANALYSIS AND DESIGN OF ALGORITHMS OHSU/OGI (Winter 2009) CS532 ANALYSIS AND DESIGN OF ALGORITHMS LECTURE 7 1 Quick Sort QuickSort 1 is a classic example of divide and conquer. The hard work is to rearrange the elements of the array A[1..n]

More information

Bin Sort. Sorting integers in Range [1,...,n] Add all elements to table and then

Bin Sort. Sorting integers in Range [1,...,n] Add all elements to table and then Sorting1 Bin Sort Sorting integers in Range [1,...,n] Add all elements to table and then Retrieve in order 1,2,3,...,n Stable Sorting Method (repeated elements will end up in their original order) Numbers

More information

CSE 613: Parallel Programming. Lecture 9 ( Divide-and-Conquer: Partitioning for Selection and Sorting )

CSE 613: Parallel Programming. Lecture 9 ( Divide-and-Conquer: Partitioning for Selection and Sorting ) CSE 613: Parallel Programming Lecture 9 ( Divide-and-Conquer: Partitioning for Selection and Sorting ) Rezaul A. Chowdhury Department of Computer Science SUNY Stony Brook Spring 2012 Parallel Partition

More information

Fast Sorting and Selection. A Lower Bound for Worst Case

Fast Sorting and Selection. A Lower Bound for Worst Case Presentation for use with the textbook, Algorithm Design and Applications, by M. T. Goodrich and R. Tamassia, Wiley, 0 Fast Sorting and Selection USGS NEIC. Public domain government image. A Lower Bound

More information

Quicksort (CLRS 7) We previously saw how the divide-and-conquer technique can be used to design sorting algorithm Merge-sort

Quicksort (CLRS 7) We previously saw how the divide-and-conquer technique can be used to design sorting algorithm Merge-sort Quicksort (CLRS 7) We previously saw how the divide-and-conquer technique can be used to design sorting algorithm Merge-sort Partition n elements array A into two subarrays of n/2 elements each Sort the

More information

Introduction to Randomized Algorithms: Quick Sort and Quick Selection

Introduction to Randomized Algorithms: Quick Sort and Quick Selection Chapter 14 Introduction to Randomized Algorithms: Quick Sort and Quick Selection CS 473: Fundamental Algorithms, Spring 2011 March 10, 2011 14.1 Introduction to Randomized Algorithms 14.2 Introduction

More information

Divide and Conquer Algorithms

Divide and Conquer Algorithms Divide and Conquer Algorithms T. M. Murali February 19, 2013 Divide and Conquer Break up a problem into several parts. Solve each part recursively. Solve base cases by brute force. Efficiently combine

More information

Outline. 1 Introduction. 3 Quicksort. 4 Analysis. 5 References. Idea. 1 Choose an element x and reorder the array as follows:

Outline. 1 Introduction. 3 Quicksort. 4 Analysis. 5 References. Idea. 1 Choose an element x and reorder the array as follows: Outline Computer Science 331 Quicksort Mike Jacobson Department of Computer Science University of Calgary Lecture #28 1 Introduction 2 Randomized 3 Quicksort Deterministic Quicksort Randomized Quicksort

More information

CSCI 3110 Assignment 6 Solutions

CSCI 3110 Assignment 6 Solutions CSCI 3110 Assignment 6 Solutions December 5, 2012 2.4 (4 pts) Suppose you are choosing between the following three algorithms: 1. Algorithm A solves problems by dividing them into five subproblems of half

More information

Outline. 1 Introduction. Merging and MergeSort. 3 Analysis. 4 Reference

Outline. 1 Introduction. Merging and MergeSort. 3 Analysis. 4 Reference Outline Computer Science 331 Sort Mike Jacobson Department of Computer Science University of Calgary Lecture #25 1 Introduction 2 Merging and 3 4 Reference Mike Jacobson (University of Calgary) Computer

More information

Sorting Algorithms. We have already seen: Selection-sort Insertion-sort Heap-sort. We will see: Bubble-sort Merge-sort Quick-sort

Sorting Algorithms. We have already seen: Selection-sort Insertion-sort Heap-sort. We will see: Bubble-sort Merge-sort Quick-sort Sorting Algorithms We have already seen: Selection-sort Insertion-sort Heap-sort We will see: Bubble-sort Merge-sort Quick-sort We will show that: O(n log n) is optimal for comparison based sorting. Bubble-Sort

More information

Review Of Topics. Review: Induction

Review Of Topics. Review: Induction Review Of Topics Asymptotic notation Solving recurrences Sorting algorithms Insertion sort Merge sort Heap sort Quick sort Counting sort Radix sort Medians/order statistics Randomized algorithm Worst-case

More information

Divide and Conquer Algorithms

Divide and Conquer Algorithms Divide and Conquer Algorithms T. M. Murali March 17, 2014 Divide and Conquer Break up a problem into several parts. Solve each part recursively. Solve base cases by brute force. Efficiently combine solutions

More information

Quicksort. Where Average and Worst Case Differ. S.V. N. (vishy) Vishwanathan. University of California, Santa Cruz

Quicksort. Where Average and Worst Case Differ. S.V. N. (vishy) Vishwanathan. University of California, Santa Cruz Quicksort Where Average and Worst Case Differ S.V. N. (vishy) Vishwanathan University of California, Santa Cruz vishy@ucsc.edu February 1, 2016 S.V. N. Vishwanathan (UCSC) CMPS101 1 / 28 Basic Idea Outline

More information

Searching. Sorting. Lambdas

Searching. Sorting. Lambdas .. s Babes-Bolyai University arthur@cs.ubbcluj.ro Overview 1 2 3 Feedback for the course You can write feedback at academicinfo.ubbcluj.ro It is both important as well as anonymous Write both what you

More information

Divide and Conquer. Recurrence Relations

Divide and Conquer. Recurrence Relations Divide and Conquer Recurrence Relations Divide-and-Conquer Strategy: Break up problem into parts. Solve each part recursively. Combine solutions to sub-problems into overall solution. 2 MergeSort Mergesort.

More information

Sorting. Chapter 11. CSE 2011 Prof. J. Elder Last Updated: :11 AM

Sorting. Chapter 11. CSE 2011 Prof. J. Elder Last Updated: :11 AM Sorting Chapter 11-1 - Sorting Ø We have seen the advantage of sorted data representations for a number of applications q Sparse vectors q Maps q Dictionaries Ø Here we consider the problem of how to efficiently

More information

Find Min and Max. Find them independantly: 2n 2. Can easily modify to get 2n 3. Should be able to do better(?) Try divide and conquer.

Find Min and Max. Find them independantly: 2n 2. Can easily modify to get 2n 3. Should be able to do better(?) Try divide and conquer. Find Min and Max Find them independantly: 2n 2. Can easily modify to get 2n 3. Should be able to do better(?) Try divide and conquer. Find_Max_Min(ELEM *L, int lower, int upper) { if (upper == lower) return

More information

Divide and Conquer Algorithms. CSE 101: Design and Analysis of Algorithms Lecture 14

Divide and Conquer Algorithms. CSE 101: Design and Analysis of Algorithms Lecture 14 Divide and Conquer Algorithms CSE 101: Design and Analysis of Algorithms Lecture 14 CSE 101: Design and analysis of algorithms Divide and conquer algorithms Reading: Sections 2.3 and 2.4 Homework 6 will

More information

Divide-and-conquer: Order Statistics. Curs: Fall 2017

Divide-and-conquer: Order Statistics. Curs: Fall 2017 Divide-and-conquer: Order Statistics Curs: Fall 2017 The divide-and-conquer strategy. 1. Break the problem into smaller subproblems, 2. recursively solve each problem, 3. appropriately combine their answers.

More information

Algorithms and Data Structures 2016 Week 5 solutions (Tues 9th - Fri 12th February)

Algorithms and Data Structures 2016 Week 5 solutions (Tues 9th - Fri 12th February) Algorithms and Data Structures 016 Week 5 solutions (Tues 9th - Fri 1th February) 1. Draw the decision tree (under the assumption of all-distinct inputs) Quicksort for n = 3. answer: (of course you should

More information

On Partial Sorting. Conrado Martínez. Univ. Politècnica de Catalunya, Spain

On Partial Sorting. Conrado Martínez. Univ. Politècnica de Catalunya, Spain Univ. Politècnica de Catalunya, Spain 10th Seminar on the Analysis of Algorithms MSRI, Berkeley, U.S.A. June 2004 1 Introduction 2 3 Introduction Partial sorting: Given an array A of n elements and a value

More information

Data Structures and Algorithms CSE 465

Data Structures and Algorithms CSE 465 Data Structures and Algorithms CSE 465 LECTURE 8 Analyzing Quick Sort Sofya Raskhodnikova and Adam Smith Reminder: QuickSort Quicksort an n-element array: 1. Divide: Partition the array around a pivot

More information

Advanced Analysis of Algorithms - Midterm (Solutions)

Advanced Analysis of Algorithms - Midterm (Solutions) Advanced Analysis of Algorithms - Midterm (Solutions) K. Subramani LCSEE, West Virginia University, Morgantown, WV {ksmani@csee.wvu.edu} 1 Problems 1. Solve the following recurrence using substitution:

More information

Class Note #14. In this class, we studied an algorithm for integer multiplication, which. 2 ) to θ(n

Class Note #14. In this class, we studied an algorithm for integer multiplication, which. 2 ) to θ(n Class Note #14 Date: 03/01/2006 [Overall Information] In this class, we studied an algorithm for integer multiplication, which improved the running time from θ(n 2 ) to θ(n 1.59 ). We then used some of

More information

A point p is said to be dominated by point q if p.x=q.x&p.y=q.y 2 true. In RAM computation model, RAM stands for Random Access Model.

A point p is said to be dominated by point q if p.x=q.x&p.y=q.y 2 true. In RAM computation model, RAM stands for Random Access Model. In analysis the upper bound means the function grows asymptotically no faster than its largest term. 1 true A point p is said to be dominated by point q if p.x=q.x&p.y=q.y 2 true In RAM computation model,

More information

Lecture 4. Quicksort

Lecture 4. Quicksort Lecture 4. Quicksort T. H. Cormen, C. E. Leiserson and R. L. Rivest Introduction to Algorithms, 3rd Edition, MIT Press, 2009 Sungkyunkwan University Hyunseung Choo choo@skku.edu Copyright 2000-2018 Networking

More information

CS 470/570 Divide-and-Conquer. Format of Divide-and-Conquer algorithms: Master Recurrence Theorem (simpler version)

CS 470/570 Divide-and-Conquer. Format of Divide-and-Conquer algorithms: Master Recurrence Theorem (simpler version) CS 470/570 Divide-and-Conquer Format of Divide-and-Conquer algorithms: Divide: Split the array or list into smaller pieces Conquer: Solve the same problem recursively on smaller pieces Combine: Build the

More information

Divide and Conquer. Arash Rafiey. 27 October, 2016

Divide and Conquer. Arash Rafiey. 27 October, 2016 27 October, 2016 Divide the problem into a number of subproblems Divide the problem into a number of subproblems Conquer the subproblems by solving them recursively or if they are small, there must be

More information

Data Structures and Algorithm Analysis (CSC317) Randomized algorithms

Data Structures and Algorithm Analysis (CSC317) Randomized algorithms Data Structures and Algorithm Analysis (CSC317) Randomized algorithms Hiring problem We always want the best hire for a job! Using employment agency to send one candidate at a time Each day, we interview

More information

Integer Sorting on the word-ram

Integer Sorting on the word-ram Integer Sorting on the word-rm Uri Zwick Tel viv University May 2015 Last updated: June 30, 2015 Integer sorting Memory is composed of w-bit words. rithmetical, logical and shift operations on w-bit words

More information

Design and Analysis of Algorithms

Design and Analysis of Algorithms CSE 101, Winter 2018 Design and Analysis of Algorithms Lecture 5: Divide and Conquer (Part 2) Class URL: http://vlsicad.ucsd.edu/courses/cse101-w18/ A Lower Bound on Convex Hull Lecture 4 Task: sort the

More information

1. Basic Algorithms: Bubble Sort

1. Basic Algorithms: Bubble Sort Sorting Algorithms Sorting Sorting. Given n elements, rearrange in ascending order. Obvious sorting applications. List files in a directory. Organize an MP3 library. List names in a phone book. Display

More information

Lecture 14: Nov. 11 & 13

Lecture 14: Nov. 11 & 13 CIS 2168 Data Structures Fall 2014 Lecturer: Anwar Mamat Lecture 14: Nov. 11 & 13 Disclaimer: These notes may be distributed outside this class only with the permission of the Instructor. 14.1 Sorting

More information

CS173 Running Time and Big-O. Tandy Warnow

CS173 Running Time and Big-O. Tandy Warnow CS173 Running Time and Big-O Tandy Warnow CS 173 Running Times and Big-O analysis Tandy Warnow Today s material We will cover: Running time analysis Review of running time analysis of Bubblesort Review

More information

Reductions, Recursion and Divide and Conquer

Reductions, Recursion and Divide and Conquer Chapter 5 Reductions, Recursion and Divide and Conquer CS 473: Fundamental Algorithms, Fall 2011 September 13, 2011 5.1 Reductions and Recursion 5.1.0.1 Reduction Reducing problem A to problem B: (A) Algorithm

More information

Fundamentals of Programming. Efficiency of algorithms November 5, 2017

Fundamentals of Programming. Efficiency of algorithms November 5, 2017 15-112 Fundamentals of Programming Efficiency of algorithms November 5, 2017 Complexity of sorting algorithms Selection Sort Bubble Sort Insertion Sort Efficiency of Algorithms A computer program should

More information

Lecture 26. Sequence Algorithms (Continued)

Lecture 26. Sequence Algorithms (Continued) Lecture 26 Sequence Algorithms (Continued) Announcements for This Lecture Lab/Finals Lab 12 is the final lab Can use Consulting hours Due next Wednesday 9:30 Final: Dec 10 th 2:00-4:30pm Study guide is

More information

CSE 591 Homework 3 Sample Solutions. Problem 1

CSE 591 Homework 3 Sample Solutions. Problem 1 CSE 591 Homework 3 Sample Solutions Problem 1 (a) Let p = max{1, k d}, q = min{n, k + d}, it suffices to find the pth and qth largest element of L and output all elements in the range between these two

More information

Reductions, Recursion and Divide and Conquer

Reductions, Recursion and Divide and Conquer CS/ECE 374: Algorithms & Models of Computation, Fall 2018 Reductions, Recursion and Divide and Conquer Lecture 10 October 2, 2018 Chandra Chekuri (UIUC) CS/ECE 374 1 Fall 2018 1 / 56 Part I Brief Intro

More information

Recommended readings: Description of Quicksort in my notes, Ch7 of your CLRS text.

Recommended readings: Description of Quicksort in my notes, Ch7 of your CLRS text. Chapter 1 Quicksort 1.1 Prerequisites You need to be familiar with the divide-and-conquer paradigm, standard notations for expressing the time-complexity of an algorithm, like the big-oh, big-omega notations.

More information

Lecture 25. Designing Sequence Algorithms

Lecture 25. Designing Sequence Algorithms Lecture 25 Designing Sequence Algorithms Announcements for This Lecture Next Week Assignment 7 There is no lab next week But Tuesday hours are open Open to EVERYONE Go for help on lab or A7 But lecture

More information

ITEC2620 Introduction to Data Structures

ITEC2620 Introduction to Data Structures ITEC2620 Introduction to Data Structures Lecture 6a Complexity Analysis Recursive Algorithms Complexity Analysis Determine how the processing time of an algorithm grows with input size What if the algorithm

More information

Sorting algorithms. Sorting algorithms

Sorting algorithms. Sorting algorithms Properties of sorting algorithms A sorting algorithm is Comparison based If it works by pairwise key comparisons. In place If only a constant number of elements of the input array are ever stored outside

More information

Longest Common Prefixes

Longest Common Prefixes Longest Common Prefixes The standard ordering for strings is the lexicographical order. It is induced by an order over the alphabet. We will use the same symbols (,

More information

Quicksort. Recurrence analysis Quicksort introduction. November 17, 2017 Hassan Khosravi / Geoffrey Tien 1

Quicksort. Recurrence analysis Quicksort introduction. November 17, 2017 Hassan Khosravi / Geoffrey Tien 1 Quicksort Recurrence analysis Quicksort introduction November 17, 2017 Hassan Khosravi / Geoffrey Tien 1 Announcement Slight adjustment to lab 5 schedule (Monday sections A, B, E) Next week (Nov.20) regular

More information

CS161: Algorithm Design and Analysis Recitation Section 3 Stanford University Week of 29 January, Problem 3-1.

CS161: Algorithm Design and Analysis Recitation Section 3 Stanford University Week of 29 January, Problem 3-1. CS161: Algorithm Design and Analysis Recitation Section 3 Stanford University Week of 29 January, 2018 Problem 3-1. (Quicksort Median-of-3 Partition) One way to improve the randomized quicksort procedure

More information

Divide-and-Conquer. a technique for designing algorithms

Divide-and-Conquer. a technique for designing algorithms Divide-and-Conquer a technique for designing algorithms decomposing instance to be solved into subinstances of the same problem solving each subinstance combining subsolutions to obtain the solution to

More information

Fundamental Algorithms

Fundamental Algorithms Chapter 2: Sorting, Winter 2018/19 1 Fundamental Algorithms Chapter 2: Sorting Jan Křetínský Winter 2018/19 Chapter 2: Sorting, Winter 2018/19 2 Part I Simple Sorts Chapter 2: Sorting, Winter 2018/19 3

More information

Fundamental Algorithms

Fundamental Algorithms Fundamental Algorithms Chapter 2: Sorting Harald Räcke Winter 2015/16 Chapter 2: Sorting, Winter 2015/16 1 Part I Simple Sorts Chapter 2: Sorting, Winter 2015/16 2 The Sorting Problem Definition Sorting

More information

Chapter 5 Divide and Conquer

Chapter 5 Divide and Conquer CMPT 705: Design and Analysis of Algorithms Spring 008 Chapter 5 Divide and Conquer Lecturer: Binay Bhattacharya Scribe: Chris Nell 5.1 Introduction Given a problem P with input size n, P (n), we define

More information

Data Structures in Java

Data Structures in Java Data Structures in Java Lecture 20: Algorithm Design Techniques 12/2/2015 Daniel Bauer 1 Algorithms and Problem Solving Purpose of algorithms: find solutions to problems. Data Structures provide ways of

More information

CSE101: Design and Analysis of Algorithms. Ragesh Jaiswal, CSE, UCSD

CSE101: Design and Analysis of Algorithms. Ragesh Jaiswal, CSE, UCSD Greedy s Greedy s Shortest path Claim 2: Let S be a subset of vertices containing s such that we know the shortest path length l(s, u) from s to any vertex in u S. Let e = (u, v) be an edge such that 1

More information

The maximum-subarray problem. Given an array of integers, find a contiguous subarray with the maximum sum. Very naïve algorithm:

The maximum-subarray problem. Given an array of integers, find a contiguous subarray with the maximum sum. Very naïve algorithm: The maximum-subarray problem Given an array of integers, find a contiguous subarray with the maximum sum. Very naïve algorithm: Brute force algorithm: At best, θ(n 2 ) time complexity 129 Can we do divide

More information

Chapter 5. Divide and Conquer CLRS 4.3. Slides by Kevin Wayne. Copyright 2005 Pearson-Addison Wesley. All rights reserved.

Chapter 5. Divide and Conquer CLRS 4.3. Slides by Kevin Wayne. Copyright 2005 Pearson-Addison Wesley. All rights reserved. Chapter 5 Divide and Conquer CLRS 4.3 Slides by Kevin Wayne. Copyright 25 Pearson-Addison Wesley. All rights reserved. Divide-and-Conquer Divide-and-conquer. Break up problem into several parts. Solve

More information

Mathematical Background. Unsigned binary numbers. Powers of 2. Logs and exponents. Mathematical Background. Today, we will review:

Mathematical Background. Unsigned binary numbers. Powers of 2. Logs and exponents. Mathematical Background. Today, we will review: Mathematical Background Mathematical Background CSE 373 Data Structures Today, we will review: Logs and eponents Series Recursion Motivation for Algorithm Analysis 5 January 007 CSE 373 - Math Background

More information

1 Divide and Conquer (September 3)

1 Divide and Conquer (September 3) The control of a large force is the same principle as the control of a few men: it is merely a question of dividing up their numbers. Sun Zi, The Art of War (c. 400 C.E.), translated by Lionel Giles (1910)

More information

Combinatorial algorithms

Combinatorial algorithms Combinatorial algorithms computing subset rank and unrank, Gray codes, k-element subset rank and unrank, computing permutation rank and unrank Jiří Vyskočil, Radek Mařík 2012 Combinatorial Generation definition:

More information

Quick Sort Notes , Spring 2010

Quick Sort Notes , Spring 2010 Quick Sort Notes 18.310, Spring 2010 0.1 Randomized Median Finding In a previous lecture, we discussed the problem of finding the median of a list of m elements, or more generally the element of rank m.

More information

Divide & Conquer. Jordi Cortadella and Jordi Petit Department of Computer Science

Divide & Conquer. Jordi Cortadella and Jordi Petit Department of Computer Science Divide & Conquer Jordi Cortadella and Jordi Petit Department of Computer Science Divide-and-conquer algorithms Strategy: Divide the problem into smaller subproblems of the same type of problem Solve the

More information

Module 1: Analyzing the Efficiency of Algorithms

Module 1: Analyzing the Efficiency of Algorithms Module 1: Analyzing the Efficiency of Algorithms Dr. Natarajan Meghanathan Professor of Computer Science Jackson State University Jackson, MS 39217 E-mail: natarajan.meghanathan@jsums.edu What is an Algorithm?

More information

Extended Algorithms Courses COMP3821/9801

Extended Algorithms Courses COMP3821/9801 NEW SOUTH WALES Extended Algorithms Courses Aleks Ignjatović School of Computer Science and Engineering University of New South Wales rithms What are we going to do in this class We will do: randomised

More information

Divide and Conquer. Andreas Klappenecker. [based on slides by Prof. Welch]

Divide and Conquer. Andreas Klappenecker. [based on slides by Prof. Welch] Divide and Conquer Andreas Klappenecker [based on slides by Prof. Welch] Divide and Conquer Paradigm An important general technique for designing algorithms: divide problem into subproblems recursively

More information

IS 709/809: Computational Methods in IS Research Fall Exam Review

IS 709/809: Computational Methods in IS Research Fall Exam Review IS 709/809: Computational Methods in IS Research Fall 2017 Exam Review Nirmalya Roy Department of Information Systems University of Maryland Baltimore County www.umbc.edu Exam When: Tuesday (11/28) 7:10pm

More information

Algorithms and Data Structures

Algorithms and Data Structures Algorithms and Data Structures, Divide and Conquer Albert-Ludwigs-Universität Freiburg Prof. Dr. Rolf Backofen Bioinformatics Group / Department of Computer Science Algorithms and Data Structures, December

More information

Parallel Numerical Algorithms

Parallel Numerical Algorithms Parallel Numerical Algorithms Chapter 13 Prof. Michael T. Heath Department of Computer Science University of Illinois at Urbana-Champaign CS 554 / CSE 512 Michael T. Heath Parallel Numerical Algorithms

More information

Partition and Select

Partition and Select Divide-Conquer-Glue Algorithms Quicksort, Quickselect and the Master Theorem Quickselect algorithm Tyler Moore CSE 3353, SMU, Dallas, TX Lecture 11 Selection Problem: find the kth smallest number of an

More information

Algorithms. Quicksort. Slide credit: David Luebke (Virginia)

Algorithms. Quicksort. Slide credit: David Luebke (Virginia) 1 Algorithms Quicksort Slide credit: David Luebke (Virginia) Sorting revisited We have seen algorithms for sorting: INSERTION-SORT, MERGESORT More generally: given a sequence of items Each item has a characteristic

More information

Minilecture 2: Sorting Algorithms

Minilecture 2: Sorting Algorithms Math/CCS 10 Professor: Padraic Bartlett Minilecture 2: Sorting Algorithms Week 1 UCSB 201 On Monday s homework, we looked at an algorithm designed to sort a list! In this class, we will study several such

More information

Divide and Conquer. Andreas Klappenecker

Divide and Conquer. Andreas Klappenecker Divide and Conquer Andreas Klappenecker The Divide and Conquer Paradigm The divide and conquer paradigm is important general technique for designing algorithms. In general, it follows the steps: - divide

More information

CSCI Honor seminar in algorithms Homework 2 Solution

CSCI Honor seminar in algorithms Homework 2 Solution CSCI 493.55 Honor seminar in algorithms Homework 2 Solution Saad Mneimneh Visiting Professor Hunter College of CUNY Problem 1: Rabin-Karp string matching Consider a binary string s of length n and another

More information

Quicksort algorithm Average case analysis

Quicksort algorithm Average case analysis Quicksort algorithm Average case analysis After today, you should be able to implement quicksort derive the average case runtime of quick sort and similar algorithms Q1-3 For any recurrence relation in

More information

COMP 250: Quicksort. Carlos G. Oliver. February 13, Carlos G. Oliver COMP 250: Quicksort February 13, / 21

COMP 250: Quicksort. Carlos G. Oliver. February 13, Carlos G. Oliver COMP 250: Quicksort February 13, / 21 COMP 250: Quicksort Carlos G. Oliver February 13, 2018 Carlos G. Oliver COMP 250: Quicksort February 13, 2018 1 / 21 1 1 https://xkcd.com/1667/ Carlos G. Oliver COMP 250: Quicksort February 13, 2018 2

More information

1. Basic Algorithms: Bubble Sort

1. Basic Algorithms: Bubble Sort Sorting Algorithms Sorting Sorting. Given n elements, rearrange in ascending order. Obvious sorting applications. List files in a directory. Organize an MP3 library. List names in a phone book. Display

More information

Lecture 1: Asymptotics, Recurrences, Elementary Sorting

Lecture 1: Asymptotics, Recurrences, Elementary Sorting Lecture 1: Asymptotics, Recurrences, Elementary Sorting Instructor: Outline 1 Introduction to Asymptotic Analysis Rate of growth of functions Comparing and bounding functions: O, Θ, Ω Specifying running

More information

5. DIVIDE AND CONQUER I

5. DIVIDE AND CONQUER I 5. DIVIDE AND CONQUER I mergesort counting inversions closest pair of points median and selection Lecture slides by Kevin Wayne Copyright 2005 Pearson-Addison Wesley http://www.cs.princeton.edu/~wayne/kleinberg-tardos

More information

Asymptotic Running Time of Algorithms

Asymptotic Running Time of Algorithms Asymptotic Complexity: leading term analysis Asymptotic Running Time of Algorithms Comparing searching and sorting algorithms so far: Count worst-case of comparisons as function of array size. Drop lower-order

More information

Divide-and-conquer. Curs 2015

Divide-and-conquer. Curs 2015 Divide-and-conquer Curs 2015 The divide-and-conquer strategy. 1. Break the problem into smaller subproblems, 2. recursively solve each problem, 3. appropriately combine their answers. Known Examples: Binary

More information

Asymptotic Algorithm Analysis & Sorting

Asymptotic Algorithm Analysis & Sorting Asymptotic Algorithm Analysis & Sorting (Version of 5th March 2010) (Based on original slides by John Hamer and Yves Deville) We can analyse an algorithm without needing to run it, and in so doing we can

More information

Algorithms, CSE, OSU Quicksort. Instructor: Anastasios Sidiropoulos

Algorithms, CSE, OSU Quicksort. Instructor: Anastasios Sidiropoulos 6331 - Algorithms, CSE, OSU Quicksort Instructor: Anastasios Sidiropoulos Sorting Given an array of integers A[1... n], rearrange its elements so that A[1] A[2]... A[n]. Quicksort Quicksort(A, p, r) if

More information

5. DIVIDE AND CONQUER I

5. DIVIDE AND CONQUER I 5. DIVIDE AND CONQUER I mergesort counting inversions closest pair of points randomized quicksort median and selection Lecture slides by Kevin Wayne Copyright 2005 Pearson-Addison Wesley http://www.cs.princeton.edu/~wayne/kleinberg-tardos

More information

Algorithms and Data Structures

Algorithms and Data Structures Charles A. Wuethrich Bauhaus-University Weimar - CogVis/MMC June 1, 2017 1/44 Space reduction mechanisms Range searching Elementary Algorithms (2D) Raster Methods Shell sort Divide and conquer Quicksort

More information

Binary Multipliers. Reading: Study Chapter 3. The key trick of multiplication is memorizing a digit-to-digit table Everything else was just adding

Binary Multipliers. Reading: Study Chapter 3. The key trick of multiplication is memorizing a digit-to-digit table Everything else was just adding Binary Multipliers The key trick of multiplication is memorizing a digit-to-digit table Everything else was just adding 2 3 4 5 6 7 8 9 2 3 4 5 6 7 8 9 2 2 4 6 8 2 4 6 8 3 3 6 9 2 5 8 2 24 27 4 4 8 2 6

More information